Use magic wake lock tag for Huawei devices.

Use a constant to enable the control condition.
Add more logging for sleep and alarms.
2026-02-11 18:29:05 +01:00 · 2018-09-07 13:32:22 +01:00 · 2018-08-30 18:10:18 +01:00 · 2018-08-30 17:43:22 +01:00 · 2018-08-08 21:27:50 -04:00 · 2018-08-07 10:38:57 -04:00
802 changed files with 35229 additions and 21016 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@ local.properties
 .idea/*
 !.idea/runConfigurations/
 !.idea/codeStyleSettings.xml
+!.idea/codeStyles
 .gradle
 build/
 *.iml
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,29 +1,27 @@
-image: registry.gitlab.com/fdroid/ci-images-base:latest
-
-cache:
-  paths:
-    - .gradle/wrapper
-    - .gradle/caches
-
-before_script:
-  - set -e
-  - export GRADLE_USER_HOME=$PWD/.gradle
-  # Accept the license for the Android build tools
-  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;26.0.2"
-  # Download OpenJDK 6 so we can compile against its standard library
-  - JDK_FILE=openjdk-6-jre-headless_6b38-1.13.10-1~deb7u1_amd64.deb
-  - if [ ! -d openjdk ]
-  - then
-  - wget -q http://ftp.uk.debian.org/debian/pool/main/o/openjdk-6/$JDK_FILE
-  - dpkg-deb -x $JDK_FILE openjdk
-  - fi
-  - export JAVA_6_HOME=$PWD/openjdk/usr/lib/jvm/java-6-openjdk-amd64
+image: briar/ci-image-android:latest

 test:
-  script:
-    - ./gradlew test
+  before_script:
+    - set -e
+    - export GRADLE_USER_HOME=$PWD/.gradle

-after_script:
-    # this file changes every time but should not be cached
+  cache:
+    paths:
+      - .gradle/wrapper
+      - .gradle/caches
+
+  script:
+    - ./gradlew --no-daemon animalSnifferMain animalSnifferTest
+    - ./gradlew --no-daemon test
+
+  after_script:
+    # these file change every time but should not be cached
    - rm -f $GRADLE_USER_HOME/caches/modules-2/modules-2.lock
    - rm -fr $GRADLE_USER_HOME/caches/*/plugin-resolution/
+
+
+test_reproducible:
+  script:
+    - "curl -X POST -F token=${RELEASE_CHECK_TOKEN} -F ref=master -F variables[RELEASE_TAG]=${CI_COMMIT_REF_NAME} https://code.briarproject.org/api/v4/projects/61/trigger/pipeline"
+  only:
+    - tags
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -0,0 +1,261 @@
+<component name="ProjectCodeStyleConfiguration">
+  <code_scheme name="Project" version="173">
+    <option name="RIGHT_MARGIN" value="100" />
+    <AndroidXmlCodeStyleSettings>
+      <option name="USE_CUSTOM_SETTINGS" value="true" />
+    </AndroidXmlCodeStyleSettings>
+    <JavaCodeStyleSettings>
+      <option name="ANNOTATION_PARAMETER_WRAP" value="1" />
+      <option name="CLASS_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
+      <option name="NAMES_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
+      <option name="PACKAGES_TO_USE_IMPORT_ON_DEMAND">
+        <value />
+      </option>
+      <option name="IMPORT_LAYOUT_TABLE">
+        <value>
+          <package name="android" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="com" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="junit" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="net" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="org" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="java" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="javax" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="" withSubpackages="true" static="false" />
+          <emptyLine />
+          <package name="" withSubpackages="true" static="true" />
+          <emptyLine />
+        </value>
+      </option>
+      <option name="JD_ALIGN_PARAM_COMMENTS" value="false" />
+      <option name="JD_ALIGN_EXCEPTION_COMMENTS" value="false" />
+    </JavaCodeStyleSettings>
+    <Objective-C-extensions>
+      <file>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Import" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Macro" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Typedef" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Enum" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Constant" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Global" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Struct" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="FunctionPredecl" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Function" />
+      </file>
+      <class>
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Property" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="Synthesize" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InitMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="StaticMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="InstanceMethod" />
+        <option name="com.jetbrains.cidr.lang.util.OCDeclarationKind" value="DeallocMethod" />
+      </class>
+      <extensions>
+        <pair source="cpp" header="h" fileNamingConvention="NONE" />
+        <pair source="c" header="h" fileNamingConvention="NONE" />
+      </extensions>
+    </Objective-C-extensions>
+    <XML>
+      <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
+    </XML>
+    <codeStyleSettings language="Groovy">
+      <indentOptions>
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
+    <codeStyleSettings language="JAVA">
+      <option name="RIGHT_MARGIN" value="80" />
+      <option name="ALIGN_MULTILINE_PARAMETERS" value="false" />
+      <option name="ALIGN_MULTILINE_RESOURCES" value="false" />
+      <option name="ALIGN_MULTILINE_FOR" value="false" />
+      <option name="SPACE_BEFORE_ARRAY_INITIALIZER_LBRACE" value="true" />
+      <option name="CALL_PARAMETERS_WRAP" value="1" />
+      <option name="METHOD_PARAMETERS_WRAP" value="1" />
+      <option name="RESOURCE_LIST_WRAP" value="1" />
+      <option name="EXTENDS_LIST_WRAP" value="1" />
+      <option name="THROWS_LIST_WRAP" value="1" />
+      <option name="EXTENDS_KEYWORD_WRAP" value="1" />
+      <option name="THROWS_KEYWORD_WRAP" value="1" />
+      <option name="METHOD_CALL_CHAIN_WRAP" value="1" />
+      <option name="BINARY_OPERATION_WRAP" value="1" />
+      <option name="TERNARY_OPERATION_WRAP" value="1" />
+      <option name="FOR_STATEMENT_WRAP" value="1" />
+      <option name="ARRAY_INITIALIZER_WRAP" value="1" />
+      <option name="ASSIGNMENT_WRAP" value="1" />
+      <option name="ASSERT_STATEMENT_WRAP" value="1" />
+      <option name="PARAMETER_ANNOTATION_WRAP" value="1" />
+      <option name="VARIABLE_ANNOTATION_WRAP" value="1" />
+      <option name="ENUM_CONSTANTS_WRAP" value="1" />
+      <indentOptions>
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
+    <codeStyleSettings language="XML">
+      <option name="FORCE_REARRANGE_MODE" value="1" />
+      <indentOptions>
+        <option name="CONTINUATION_INDENT_SIZE" value="4" />
+        <option name="USE_TAB_CHARACTER" value="true" />
+        <option name="SMART_TABS" value="true" />
+      </indentOptions>
+      <arrangement>
+        <rules>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:android</NAME>
+                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>xmlns:.*</NAME>
+                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:id</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:name</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>name</NAME>
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>style</NAME>
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:layout_width</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:layout_height</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:layout_.*</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:width</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:height</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_NAMESPACE>.*</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+        </rules>
+      </arrangement>
+    </codeStyleSettings>
+  </code_scheme>
+</component>
--- a/.idea/codeStyles/codeStyleConfig.xml
+++ b/.idea/codeStyles/codeStyleConfig.xml
@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
+  </state>
+</component>
--- a/.idea/runConfigurations/H2_Performance_Test.xml
+++ b/.idea/runConfigurations/H2_Performance_Test.xml
@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="H2 Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
+    <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.H2DatabasePerformanceTest" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>
--- a/.idea/runConfigurations/HyperSQL_Performance_Test.xml
+++ b/.idea/runConfigurations/HyperSQL_Performance_Test.xml
@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="HyperSQL Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
+    <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.HyperSqlDatabasePerformanceTest" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>
--- a/bramble-android/build.gradle
+++ b/bramble-android/build.gradle
@@ -1,20 +1,18 @@
-import de.undercouch.gradle.tasks.download.Download
-import de.undercouch.gradle.tasks.download.Verify
-
 apply plugin: 'com.android.library'
 apply plugin: 'witness'
-apply plugin: 'de.undercouch.download'

 android {
 	compileSdkVersion 27
-	buildToolsVersion '26.0.2'
+	buildToolsVersion '27.0.3'

 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 26
-		versionCode 1612
-		versionName "0.16.12"
+		versionCode 10011
+		versionName "1.0.11"
 		consumerProguardFiles 'proguard-rules.txt'
+
+		testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
 	}

 	compileOptions {
@@ -23,73 +21,109 @@ android {
 	}
 }

+configurations {
+	tor
+}
+
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	implementation fileTree(dir: 'libs', include: '*.jar')
+	implementation 'org.briarproject:jtorctl:0.3'
+	tor 'org.briarproject:tor-android:0.2.9.15@zip'

 	annotationProcessor 'com.google.dagger:dagger-compiler:2.0.2'

 	compileOnly 'javax.annotation:jsr250-api:1.0'
+
+	androidTestImplementation project(path: ':bramble-api', configuration: 'testOutput')
+	androidTestImplementation project(path: ':bramble-core', configuration: 'testOutput')
+	androidTestImplementation 'com.android.support.test:runner:1.0.2'
+	androidTestAnnotationProcessor 'com.google.dagger:dagger-compiler:2.0.2'
+	androidTestCompileOnly 'javax.annotation:jsr250-api:1.0'
 }

 dependencyVerification {
 	verify = [
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.android.tools.analytics-library:protos:26.1.3:protos-26.1.3.jar:818c9f256f141d9dafec03a1aa2b94d240b2c140acfd7ee31a8b3e6c2b9479e3',
+			'com.android.tools.analytics-library:shared:26.1.3:shared-26.1.3.jar:7110706c7ada96c8b6f5ca80c478291bc7899d46277de2c48527e045442401a3',
+			'com.android.tools.analytics-library:tracker:26.1.3:tracker-26.1.3.jar:4155424bf2ce4872da83332579a1707252bc66cbd77c5144fdc4483d0f2e1418',
+			'com.android.tools.build:apksig:3.1.3:apksig-3.1.3.jar:7e1f8e675a6e768e5b56405e41d6c3cc05befe62e601b04177de1029902c9c89',
+			'com.android.tools.build:builder-model:3.1.3:builder-model-3.1.3.jar:06ad1c422d679fc698451479cb40ba863849d67bfd1de23f6d2c16d78b024b0b',
+			'com.android.tools.build:builder-test-api:3.1.3:builder-test-api-3.1.3.jar:4d989f780436794f0f8b2f50e9e079b786571eac90f26c208ab2ae6d4012f389',
+			'com.android.tools.build:builder:3.1.3:builder-3.1.3.jar:8a1092012c89d0ec1ee2eff09c5708c71ef4482a6862df8d3a44a67fccace01c',
+			'com.android.tools.build:gradle-api:3.1.3:gradle-api-3.1.3.jar:01e4df521456aef66514336f1d492346730dd1fb8f6433a89f62da834941ed72',
+			'com.android.tools.build:manifest-merger:26.1.3:manifest-merger-26.1.3.jar:1e4fc7e932adb4607082409800e5e6fccb42e6c5360ae5990094bf522f3ada55',
+			'com.android.tools.ddms:ddmlib:26.1.3:ddmlib-26.1.3.jar:c54931cd68df5d1ea2923b3b320eae47cd2307a5a916bb8674c0acf93cd1d3cd',
+			'com.android.tools.external.com-intellij:intellij-core:26.1.3:intellij-core-26.1.3.jar:af67f5535fef2e1a28b1007a4acb8c5deb6a1e33b8afe7b11d012c9e778ebcec',
+			'com.android.tools.external.com-intellij:kotlin-compiler:26.1.3:kotlin-compiler-26.1.3.jar:c746d2859dc11cc05c84b692b3498d3a621e0929511f8440ee009c6557838fd4',
+			'com.android.tools.external.org-jetbrains:uast:26.1.3:uast-26.1.3.jar:3f3f6651d0c7685a77ecb22e9c82d6b49fdf24322c17360768dc530678f43265',
+			'com.android.tools.layoutlib:layoutlib-api:26.1.3:layoutlib-api-26.1.3.jar:10bc73ce706c45629872d6a999dbe12116df64e24f47ff93b7b13121ff57b4b0',
+			'com.android.tools.lint:lint-api:26.1.3:lint-api-26.1.3.jar:6f97323f9af8deda86278717885b5c927f3766757db89709f52d11d42b6fb751',
+			'com.android.tools.lint:lint-checks:26.1.3:lint-checks-26.1.3.jar:73c3d53784c9ce3e6d5968506581918e0179645d20809927ca4a001dd766b001',
+			'com.android.tools.lint:lint-gradle-api:26.1.3:lint-gradle-api-26.1.3.jar:7ca3c4866ec21dc21d53a9d86f752b77ace6f6c610a0c9dc877313856c733d9d',
+			'com.android.tools.lint:lint-gradle:26.1.3:lint-gradle-26.1.3.jar:db0c354b8f4b6f6637e31f91c564785a59ff896325331fcbc3de7458e0b6c067',
+			'com.android.tools.lint:lint-kotlin:26.1.3:lint-kotlin-26.1.3.jar:94e2b0f4565a241561cfb8fc1222bb3f132a3b98d2a90421dbb72ee8358e7d68',
+			'com.android.tools.lint:lint:26.1.3:lint-26.1.3.jar:8d5f32c989c6d191d712e90ad3ca2d1c409313599551d04d834caa44d26c78df',
+			'com.android.tools:annotations:26.1.3:annotations-26.1.3.jar:c950430b24ac5d58fc97e7283b8f0115f99587e76e08b4e1e2aaa780f2d77323',
+			'com.android.tools:common:26.1.3:common-26.1.3.jar:7c31a90581a148ab219f615a59667f0dded7fa39b248529784474da3c2274ef2',
+			'com.android.tools:dvlib:26.1.3:dvlib-26.1.3.jar:0cae87906f53d3f1088366a916ed180a7312b6d9919b90797f238875c8492855',
+			'com.android.tools:repository:26.1.3:repository-26.1.3.jar:52d4539cc68db91b261e2a33b2c8206b26e05539078758dc28cfb3854adb4f59',
+			'com.android.tools:sdk-common:26.1.3:sdk-common-26.1.3.jar:1948603ca9ff22c7ebb3178000bffa3a9dd2ca1cc5cb0c793cae08468b8fcfc1',
+			'com.android.tools:sdklib:26.1.3:sdklib-26.1.3.jar:4adcfaad9514607098d2c51503c39811112d3050f4d1e744c01c7f08f591032b',
+			'com.google.code.findbugs:jsr305:1.3.9:jsr305-1.3.9.jar:905721a0eea90a81534abb7ee6ef4ea2e5e645fa1def0a5cd88402df1b46c9ed',
+			'com.google.code.gson:gson:2.7:gson-2.7.jar:2d43eb5ea9e133d2ee2405cc14f5ee08951b8361302fdd93494a3a997b508d32',
 			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
 			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
 			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'com.google.errorprone:error_prone_annotations:2.0.18:error_prone_annotations-2.0.18.jar:cb4cfad870bf563a07199f3ebea5763f0dec440fcda0b318640b1feaa788656b',
 			'com.google.guava:guava:18.0:guava-18.0.jar:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
-			'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
+			'com.google.guava:guava:22.0:guava-22.0.jar:1158e94c7de4da480873f0b4ab4a1da14c0d23d4b1902cc94a58a6f0f9ab579e',
+			'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:40ceb7157feb263949e0f503fe5f71689333a621021aa20ce0d0acee3badaa0f',
+			'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
+			'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
+			'com.googlecode.json-simple:json-simple:1.1:json-simple-1.1.jar:2d9484f4c649f708f47f9a479465fc729770ee65617dca3011836602264f6439',
+			'com.squareup:javawriter:2.5.0:javawriter-2.5.0.jar:fcfb09fb0ea0aa97d3cfe7ea792398081348e468f126b3603cb3803f240197f0',
+			'com.sun.activation:javax.activation:1.2.0:javax.activation-1.2.0.jar:993302b16cd7056f21e779cc577d175a810bb4900ef73cd8fbf2b50f928ba9ce',
+			'com.sun.istack:istack-commons-runtime:2.21:istack-commons-runtime-2.21.jar:c33e67a0807095f02a0e2da139412dd7c4f9cc1a4c054b3e434f96831ba950f4',
+			'com.sun.xml.fastinfoset:FastInfoset:1.2.13:FastInfoset-1.2.13.jar:27a77db909f3c2833c0b1a37c55af1db06045118ad2eed96ce567b6632bce038',
+			'commons-codec:commons-codec:1.6:commons-codec-1.6.jar:54b34e941b8e1414bd3e40d736efd3481772dc26db3296f6aa45cec9f6203d86',
+			'commons-logging:commons-logging:1.1.1:commons-logging-1.1.1.jar:ce6f913cad1f0db3aad70186d65c5bc7ffcc9a99e3fe8e0b137312819f7c362f',
+			'it.unimi.dsi:fastutil:7.2.0:fastutil-7.2.0.jar:74fa208043740642f7e6eb09faba15965218ad2f50ce3020efb100136e4b591c',
 			'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
 			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
-			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128-runtime.jar:e357a0f1d573c2f702a273992b1b6cb661734f66311854efb3778a888515c5b5',
-			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128.jar:47b4bec6df11a1118da3953da8b9fa1e7079d6fec857faa1a3cf912e53a6fd4e',
-			'org.jacoco:org.jacoco.ant:0.7.4.201502262128:org.jacoco.ant-0.7.4.201502262128.jar:013ce2a68ba57a3c59215ae0dec4df3498c078062a38c3b94c841fc14450f283',
-			'org.jacoco:org.jacoco.core:0.7.4.201502262128:org.jacoco.core-0.7.4.201502262128.jar:ec4c74554312fac5116350164786f91b35c9e082fa4ea598bfa42b5db05d7abb',
-			'org.jacoco:org.jacoco.report:0.7.4.201502262128:org.jacoco.report-0.7.4.201502262128.jar:7a3554c605e088e7e323b1084656243f0444fa353e2f2dee1f1a4204eb64ff09',
-			'org.ow2.asm:asm-debug-all:5.0.1:asm-debug-all-5.0.1.jar:4734de5b515a454b0096db6971fb068e5f70e6f10bbee2b3bd2fdfe5d978ed57',
+			'javax.xml.bind:jaxb-api:2.2.12-b140109.1041:jaxb-api-2.2.12-b140109.1041.jar:b5e60cd8b7b5ff01ce4a74c5dd008f4fbd14ced3495d0b47b85cfedc182211f2',
+			'net.sf.jopt-simple:jopt-simple:4.9:jopt-simple-4.9.jar:26c5856e954b5f864db76f13b86919b59c6eecf9fd930b96baa8884626baf2f5',
+			'net.sf.kxml:kxml2:2.3.0:kxml2-2.3.0.jar:f264dd9f79a1fde10ce5ecc53221eff24be4c9331c830b7d52f2f08a7b633de2',
+			'org.apache.commons:commons-compress:1.12:commons-compress-1.12.jar:2c1542faf343185b7cab9c3d55c8ae5471d6d095d3887a4adefdbdf2984dc0b6',
+			'org.apache.httpcomponents:httpclient:4.2.6:httpclient-4.2.6.jar:362e9324ee7c697e21279e20077b52737ddef3f1b2c1a7abe5ad34b465145550',
+			'org.apache.httpcomponents:httpcore:4.2.5:httpcore-4.2.5.jar:e5e82da4cc66c8d917bbf743e3c0752efe8522735e7fc9dbddb65bccea81cfe9',
+			'org.apache.httpcomponents:httpmime:4.1:httpmime-4.1.jar:31629566148e8a47688ae43b420abc3ecd783ed15b33bebc00824bf24c9b15aa',
+			'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
+			'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
+			'org.briarproject:jtorctl:0.3:jtorctl-0.3.jar:f2939238a097898998432effe93b0334d97a787972ab3a91a8973a1d309fc864',
+			'org.briarproject:tor-android:0.2.9.15:tor-android-0.2.9.15.zip:34a6474ee219ffa52e0f3393e917dda6ed03d320b02247d4fa5075aa4094ee6d',
+			'org.codehaus.groovy:groovy-all:2.4.12:groovy-all-2.4.12.jar:6a56af4bd48903d56bec62821876cadefafd007360cc6bd0d8f7aa8d72b38be4',
+			'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
+			'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
+			'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
+			'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
+			'org.jetbrains.kotlin:kotlin-reflect:1.2.0:kotlin-reflect-1.2.0.jar:4f48a872bad6e4d9c053f4ad610d11e4012ad7e58dc19a03dd5eb811f36069dd',
+			'org.jetbrains.kotlin:kotlin-stdlib-jre7:1.2.0:kotlin-stdlib-jre7-1.2.0.jar:c7a20fb951d437797afe8980aff6c1e5a03f310c661ba58ba1d4fa90cb0f2926',
+			'org.jetbrains.kotlin:kotlin-stdlib-jre8:1.2.0:kotlin-stdlib-jre8-1.2.0.jar:633524eee6ef1941f7cb1dab7ee3927b0a221ceee9047aeb5515f4cbb990c82a',
+			'org.jetbrains.kotlin:kotlin-stdlib:1.2.0:kotlin-stdlib-1.2.0.jar:05cfd9f5ac0b41910703a8925f7211a495909b27a2ffdd1c5106f1689aeafcd4',
+			'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
+			'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
+			'org.jvnet.staxex:stax-ex:1.7.7:stax-ex-1.7.7.jar:a31ff7d77163c0deb09e7fee59ad35ae44c2cee2cc8552a116ccd1583d813fb4',
+			'org.ow2.asm:asm-analysis:5.1:asm-analysis-5.1.jar:a34658f5c5de4b573eef21131cc32cc25f7b66407944f312b28ec2e56abb1fa9',
+			'org.ow2.asm:asm-commons:5.1:asm-commons-5.1.jar:97b3786e1f55e74bddf8ad102bf50e33bbcbc1f6b7fd7b36f0bbbb25cd4981be',
+			'org.ow2.asm:asm-tree:5.1:asm-tree-5.1.jar:c0de2bbc4cb8297419659813ecd4ed1d077ed1dd5c1f5544cc5143e493e84c10',
+			'org.ow2.asm:asm-util:5.1:asm-util-5.1.jar:ee032c39ae5e3cd099148fbba9a2124f9ed613e5cb93e03ee0fa8808ce364040',
+			'org.ow2.asm:asm:5.1:asm-5.1.jar:d2da399a9967c69f0a21739256fa79d284222c223082cacadc17372244764b54',
 	]
 }

-ext.torBinaryDir = 'src/main/res/raw'
-ext.torVersion = '0.2.9.12'
-ext.geoipVersion = '2017-09-06'
-ext.torDownloadUrl = 'https://briarproject.org/build/'
-
-def torBinaries = [
-		"tor_arm"    : '8ed0b347ffed1d6a4d2fd14495118eb92be83e9cc06e057e15220dc288b31688',
-		"tor_arm_pie": '64403262511c29f462ca5e7c7621bfc3c944898364d1d5ad35a016bb8a034283',
-		"tor_x86"    : '61e014607a2079bcf1646289c67bff6372b1aded6e1d8d83d7791efda9a4d5ab',
-		"tor_x86_pie": '18fbc98356697dd0895836ab46d5c9877d1c539193464f7db1e82a65adaaf288',
-		"geoip"      : 'fe49d3adb86d3c512373101422a017dbb86c85a570524663f09dd8ce143a24f3'
-]
-
-def downloadBinary(name) {
-	return tasks.create("downloadBinary${name}", Download) {
-		src "${torDownloadUrl}${name}.zip"
-				.replace('tor_', "tor-${torVersion}-")
-				.replace('geoip', "geoip-${geoipVersion}")
-				.replaceAll('_', '-')
-		dest "${torBinaryDir}/${name}.zip"
-		onlyIfNewer true
-	}
-}
-
-def verifyBinary(name, chksum) {
-	return tasks.create([
-			name     : "verifyBinary${name}",
-			type     : Verify,
-			dependsOn: downloadBinary(name)]) {
-		src "${torBinaryDir}/${name}.zip"
-		algorithm 'SHA-256'
-		checksum chksum
-	}
-}
-
 project.afterEvaluate {
-	torBinaries.every { key, value ->
-		preBuild.dependsOn.add(verifyBinary(key, value))
+	copy {
+		from configurations.tor.collect { zipTree(it) }
+		into 'src/main/res/raw'
 	}
 }
--- a/bramble-android/libs/jtorctl-briar.jar
+++ b/bramble-android/libs/jtorctl-briar.jar
--- a/bramble-android/proguard-rules.txt
+++ b/bramble-android/proguard-rules.txt
@@ -8,6 +8,10 @@
 -dontwarn dagger.**
 -dontnote dagger.**

+-keep class net.i2p.crypto.eddsa.** { *; }
+
+-keep class org.whispersystems.curve25519.** { *; }
+
 -dontwarn sun.misc.Unsafe
 -dontnote com.google.common.**

--- a/bramble-android/src/androidTest/java/org/briarproject/bramble/IntegrationTestComponent.java
+++ b/bramble-android/src/androidTest/java/org/briarproject/bramble/IntegrationTestComponent.java
@@ -0,0 +1,23 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.event.EventModule;
+import org.briarproject.bramble.plugin.PluginModule;
+import org.briarproject.bramble.plugin.tor.BridgeTest;
+import org.briarproject.bramble.system.SystemModule;
+
+import javax.inject.Singleton;
+
+import dagger.Component;
+
+@Singleton
+@Component(modules = {
+		BrambleAndroidModule.class,
+		PluginModule.class,  // needed for BackoffFactory
+		EventModule.class,
+		SystemModule.class,
+})
+public interface IntegrationTestComponent {
+
+	void inject(BridgeTest init);
+
+}
--- a/bramble-android/src/androidTest/java/org/briarproject/bramble/plugin/tor/BridgeTest.java
+++ b/bramble-android/src/androidTest/java/org/briarproject/bramble/plugin/tor/BridgeTest.java
@@ -0,0 +1,126 @@
+package org.briarproject.bramble.plugin.tor;
+
+import android.content.Context;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.briarproject.bramble.DaggerIntegrationTestComponent;
+import org.briarproject.bramble.IntegrationTestComponent;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.LocationUtils;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import java.util.logging.Logger;
+
+import javax.inject.Inject;
+import javax.net.SocketFactory;
+
+import static android.support.test.InstrumentationRegistry.getTargetContext;
+import static java.util.Collections.singletonList;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+
+@RunWith(AndroidJUnit4.class)
+public class BridgeTest extends BrambleTestCase {
+
+	private final static long TIMEOUT = SECONDS.toMillis(23);
+
+	private final static Logger LOG =
+			Logger.getLogger(BridgeTest.class.getSimpleName());
+
+	@Inject
+	EventBus eventBus;
+	@Inject
+	BackoffFactory backoffFactory;
+	@Inject
+	Clock clock;
+
+	private final Context appContext = getTargetContext();
+	private final CircumventionProvider circumventionProvider;
+	private final List<String> bridges;
+	private TorPluginFactory factory;
+	private volatile int currentBridge = 0;
+
+	public BridgeTest() {
+		super();
+		circumventionProvider = new CircumventionProvider() {
+			@Override
+			public boolean isTorProbablyBlocked(String countryCode) {
+				return true;
+			}
+
+			@Override
+			public boolean doBridgesWork(String countryCode) {
+				return true;
+			}
+
+			@Override
+			public List<String> getBridges() {
+				return singletonList(bridges.get(currentBridge));
+			}
+		};
+		bridges = new CircumventionProviderImpl(appContext).getBridges();
+	}
+
+	@Before
+	public void setUp() {
+		IntegrationTestComponent component =
+				DaggerIntegrationTestComponent.builder().build();
+		component.inject(this);
+
+		Executor ioExecutor = Executors.newCachedThreadPool();
+		ScheduledExecutorService scheduler = new ScheduledThreadPoolExecutor(1);
+		LocationUtils locationUtils = () -> "US";
+		SocketFactory torSocketFactory = SocketFactory.getDefault();
+
+		factory = new TorPluginFactory(ioExecutor, scheduler, appContext,
+				locationUtils, eventBus, torSocketFactory,
+				backoffFactory, circumventionProvider, clock);
+	}
+
+	@Test
+	public void testBridges() throws Exception {
+		assertTrue(bridges.size() > 0);
+
+		for (int i = 0; i < bridges.size(); i++) {
+			testBridge(i);
+		}
+	}
+
+	private void testBridge(int bridge) throws Exception {
+		DuplexPlugin duplexPlugin =
+				factory.createPlugin(new TorPluginCallBack());
+		assertNotNull(duplexPlugin);
+		TorPlugin plugin = (TorPlugin) duplexPlugin;
+
+		currentBridge = bridge;
+		LOG.warning("Testing " + bridges.get(currentBridge));
+		try {
+			plugin.start();
+			long start = clock.currentTimeMillis();
+			while (clock.currentTimeMillis() - start < TIMEOUT) {
+				if (plugin.isRunning()) return;
+				clock.sleep(500);
+			}
+			if (!plugin.isRunning()) {
+				fail("Could not connect to Tor within timeout.");
+			}
+		} finally {
+			plugin.stop();
+		}
+	}
+
+}
--- a/bramble-android/src/androidTest/java/org/briarproject/bramble/plugin/tor/TorPluginCallBack.java
+++ b/bramble-android/src/androidTest/java/org/briarproject/bramble/plugin/tor/TorPluginCallBack.java
@@ -0,0 +1,54 @@
+package org.briarproject.bramble.plugin.tor;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.api.settings.Settings;
+
+@NotNullByDefault
+public class TorPluginCallBack implements DuplexPluginCallback {
+
+	@Override
+	public void incomingConnectionCreated(DuplexTransportConnection d) {
+
+	}
+
+	@Override
+	public void outgoingConnectionCreated(ContactId c,
+			DuplexTransportConnection d) {
+
+	}
+
+	@Override
+	public Settings getSettings() {
+		return new Settings();
+	}
+
+	@Override
+	public TransportProperties getLocalProperties() {
+		return new TransportProperties();
+	}
+
+	@Override
+	public void mergeSettings(Settings s) {
+
+	}
+
+	@Override
+	public void mergeLocalProperties(TransportProperties p) {
+
+	}
+
+	@Override
+	public void transportEnabled() {
+
+	}
+
+	@Override
+	public void transportDisabled() {
+
+	}
+
+}
--- a/bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidModule.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidModule.java
@@ -1,13 +1,25 @@
 package org.briarproject.bramble;

-import org.briarproject.bramble.plugin.AndroidPluginModule;
+import android.app.Application;
+
+import org.briarproject.bramble.plugin.tor.CircumventionProvider;
+import org.briarproject.bramble.plugin.tor.CircumventionProviderImpl;
 import org.briarproject.bramble.system.AndroidSystemModule;

+import javax.inject.Singleton;
+
 import dagger.Module;
+import dagger.Provides;

@Module(includes = {
-		AndroidPluginModule.class,
 		AndroidSystemModule.class
 })
 public class BrambleAndroidModule {
+
+	@Provides
+	@Singleton
+	CircumventionProvider provideCircumventionProvider(Application app) {
+		return new CircumventionProviderImpl(app.getApplicationContext());
+	}
+
 }
--- a/bramble-android/src/main/java/org/briarproject/bramble/PowerTestingConstants.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/PowerTestingConstants.java
@@ -0,0 +1,8 @@
+package org.briarproject.bramble;
+
+public interface PowerTestingConstants {
+
+	int WAKE_LOCK_DURATION = 5000;
+	int ALARM_DELAY = 5000;
+	boolean USE_TOR_WAKE_LOCK = true;
+}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/AndroidPluginModule.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/AndroidPluginModule.java
@@ -1,65 +0,0 @@
-package org.briarproject.bramble.plugin;
-
-import android.app.Application;
-import android.content.Context;
-
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
-import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
-import org.briarproject.bramble.api.reporting.DevReporter;
-import org.briarproject.bramble.api.system.AndroidExecutor;
-import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.plugin.droidtooth.DroidtoothPluginFactory;
-import org.briarproject.bramble.plugin.tcp.AndroidLanTcpPluginFactory;
-import org.briarproject.bramble.plugin.tor.TorPluginFactory;
-
-import java.security.SecureRandom;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.concurrent.Executor;
-
-import javax.net.SocketFactory;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class AndroidPluginModule {
-
-	@Provides
-	PluginConfig providePluginConfig(@IoExecutor Executor ioExecutor,
-			AndroidExecutor androidExecutor, SecureRandom random,
-			SocketFactory torSocketFactory, BackoffFactory backoffFactory,
-			Application app, LocationUtils locationUtils, DevReporter reporter,
-			EventBus eventBus) {
-		Context appContext = app.getApplicationContext();
-		DuplexPluginFactory bluetooth = new DroidtoothPluginFactory(ioExecutor,
-				androidExecutor, appContext, random, eventBus, backoffFactory);
-		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, appContext,
-				locationUtils, reporter, eventBus, torSocketFactory,
-				backoffFactory);
-		DuplexPluginFactory lan = new AndroidLanTcpPluginFactory(ioExecutor,
-				backoffFactory, appContext);
-		Collection<DuplexPluginFactory> duplex =
-				Arrays.asList(bluetooth, tor, lan);
-		@NotNullByDefault
-		PluginConfig pluginConfig = new PluginConfig() {
-
-			@Override
-			public Collection<DuplexPluginFactory> getDuplexFactories() {
-				return duplex;
-			}
-
-			@Override
-			public Collection<SimplexPluginFactory> getSimplexFactories() {
-				return Collections.emptyList();
-			}
-		};
-		return pluginConfig;
-	}
-}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java
@@ -0,0 +1,210 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothServerSocket;
+import android.bluetooth.BluetoothSocket;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.PluginException;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.util.AndroidUtils;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
+import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
+import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
+import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
+import static android.bluetooth.BluetoothAdapter.STATE_OFF;
+import static android.bluetooth.BluetoothAdapter.STATE_ON;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
+
+	private static final Logger LOG =
+			Logger.getLogger(AndroidBluetoothPlugin.class.getName());
+
+	private final AndroidExecutor androidExecutor;
+	private final Context appContext;
+
+	private volatile boolean wasEnabledByUs = false;
+	private volatile BluetoothStateReceiver receiver = null;
+
+	// Non-null if the plugin started successfully
+	private volatile BluetoothAdapter adapter = null;
+
+	AndroidBluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
+			Executor ioExecutor, AndroidExecutor androidExecutor,
+			Context appContext, SecureRandom secureRandom, Backoff backoff,
+			DuplexPluginCallback callback, int maxLatency) {
+		super(connectionLimiter, ioExecutor, secureRandom, backoff, callback,
+				maxLatency);
+		this.androidExecutor = androidExecutor;
+		this.appContext = appContext;
+	}
+
+	@Override
+	public void start() throws PluginException {
+		super.start();
+		// Listen for changes to the Bluetooth state
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(ACTION_STATE_CHANGED);
+		filter.addAction(ACTION_SCAN_MODE_CHANGED);
+		receiver = new BluetoothStateReceiver();
+		appContext.registerReceiver(receiver, filter);
+	}
+
+	@Override
+	public void stop() {
+		super.stop();
+		if (receiver != null) appContext.unregisterReceiver(receiver);
+	}
+
+	@Override
+	void initialiseAdapter() throws IOException {
+		// BluetoothAdapter.getDefaultAdapter() must be called on a thread
+		// with a message queue, so submit it to the AndroidExecutor
+		try {
+			adapter = androidExecutor.runOnBackgroundThread(
+					BluetoothAdapter::getDefaultAdapter).get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new IOException(e);
+		}
+		if (adapter == null)
+			throw new IOException("Bluetooth is not supported");
+	}
+
+	@Override
+	boolean isAdapterEnabled() {
+		return adapter != null && adapter.isEnabled();
+	}
+
+	@Override
+	void enableAdapter() {
+		if (adapter != null && !adapter.isEnabled()) {
+			if (adapter.enable()) {
+				LOG.info("Enabling Bluetooth");
+				wasEnabledByUs = true;
+			} else {
+				LOG.info("Could not enable Bluetooth");
+			}
+		}
+	}
+
+	@Override
+	void disableAdapterIfEnabledByUs() {
+		if (isAdapterEnabled() && wasEnabledByUs) {
+			if (adapter.disable()) LOG.info("Disabling Bluetooth");
+			else LOG.info("Could not disable Bluetooth");
+			wasEnabledByUs = false;
+		}
+	}
+
+	@Override
+	void setEnabledByUs() {
+		wasEnabledByUs = true;
+	}
+
+	@Override
+	@Nullable
+	String getBluetoothAddress() {
+		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
+		return address.isEmpty() ? null : address;
+	}
+
+	@Override
+	BluetoothServerSocket openServerSocket(String uuid) throws IOException {
+		return adapter.listenUsingInsecureRfcommWithServiceRecord(
+				"RFCOMM", UUID.fromString(uuid));
+	}
+
+	@Override
+	void tryToClose(@Nullable BluetoothServerSocket ss) {
+		try {
+			if (ss != null) ss.close();
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	@Override
+	DuplexTransportConnection acceptConnection(BluetoothServerSocket ss)
+			throws IOException {
+		return wrapSocket(ss.accept());
+	}
+
+	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
+		return new AndroidBluetoothTransportConnection(this,
+				connectionLimiter, s);
+	}
+
+	@Override
+	boolean isValidAddress(String address) {
+		return BluetoothAdapter.checkBluetoothAddress(address);
+	}
+
+	@Override
+	DuplexTransportConnection connectTo(String address, String uuid)
+			throws IOException {
+		BluetoothDevice d = adapter.getRemoteDevice(address);
+		UUID u = UUID.fromString(uuid);
+		BluetoothSocket s = null;
+		try {
+			s = d.createInsecureRfcommSocketToServiceRecord(u);
+			s.connect();
+			return wrapSocket(s);
+		} catch (IOException e) {
+			tryToClose(s);
+			throw e;
+		}
+	}
+
+	private void tryToClose(@Nullable Closeable c) {
+		try {
+			if (c != null) c.close();
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private class BluetoothStateReceiver extends BroadcastReceiver {
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			int state = intent.getIntExtra(EXTRA_STATE, 0);
+			if (state == STATE_ON) onAdapterEnabled();
+			else if (state == STATE_OFF) onAdapterDisabled();
+			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
+			if (scanMode == SCAN_MODE_NONE) {
+				LOG.info("Scan mode: None");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE) {
+				LOG.info("Scan mode: Connectable");
+			} else if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
+				LOG.info("Scan mode: Discoverable");
+			}
+		}
+	}
+}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java
@@ -1,4 +1,4 @@
-package org.briarproject.bramble.plugin.droidtooth;
+package org.briarproject.bramble.plugin.bluetooth;

 import android.content.Context;

@@ -21,7 +21,7 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;

@Immutable
@NotNullByDefault
-public class DroidtoothPluginFactory implements DuplexPluginFactory {
+public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {

 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
 	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
@@ -35,7 +35,7 @@ public class DroidtoothPluginFactory implements DuplexPluginFactory {
 	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;

-	public DroidtoothPluginFactory(Executor ioExecutor,
+	public AndroidBluetoothPluginFactory(Executor ioExecutor,
 			AndroidExecutor androidExecutor, Context appContext,
 			SecureRandom secureRandom, EventBus eventBus,
 			BackoffFactory backoffFactory) {
@@ -59,11 +59,13 @@ public class DroidtoothPluginFactory implements DuplexPluginFactory {

 	@Override
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
+		BluetoothConnectionLimiter connectionLimiter =
+				new BluetoothConnectionLimiterImpl();
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		DroidtoothPlugin plugin = new DroidtoothPlugin(ioExecutor,
-				androidExecutor, appContext, secureRandom, backoff, callback,
-				MAX_LATENCY);
+		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
+				connectionLimiter, ioExecutor, androidExecutor, appContext,
+				secureRandom, backoff, callback, MAX_LATENCY);
 		eventBus.addListener(plugin);
 		return plugin;
 	}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java
@@ -1,4 +1,4 @@
-package org.briarproject.bramble.plugin.droidtooth;
+package org.briarproject.bramble.plugin.bluetooth;

 import android.bluetooth.BluetoothSocket;

@@ -11,12 +11,17 @@ import java.io.InputStream;
 import java.io.OutputStream;

@NotNullByDefault
-class DroidtoothTransportConnection extends AbstractDuplexTransportConnection {
+class AndroidBluetoothTransportConnection
+		extends AbstractDuplexTransportConnection {

+	private final BluetoothConnectionLimiter connectionManager;
 	private final BluetoothSocket socket;

-	DroidtoothTransportConnection(Plugin plugin, BluetoothSocket socket) {
+	AndroidBluetoothTransportConnection(Plugin plugin,
+			BluetoothConnectionLimiter connectionManager,
+			BluetoothSocket socket) {
 		super(plugin);
+		this.connectionManager = connectionManager;
 		this.socket = socket;
 	}

@@ -32,6 +37,10 @@ class DroidtoothTransportConnection extends AbstractDuplexTransportConnection {

 	@Override
 	protected void closeConnection(boolean exception) throws IOException {
-		socket.close();
+		try {
+			socket.close();
+		} finally {
+			connectionManager.connectionClosed(this);
+		}
 	}
 }
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPlugin.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPlugin.java
@@ -1,490 +0,0 @@
-package org.briarproject.bramble.plugin.droidtooth;
-
-import android.bluetooth.BluetoothAdapter;
-import android.bluetooth.BluetoothDevice;
-import android.bluetooth.BluetoothServerSocket;
-import android.bluetooth.BluetoothSocket;
-import android.content.BroadcastReceiver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.IntentFilter;
-
-import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
-import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
-import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
-import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.system.AndroidExecutor;
-import org.briarproject.bramble.util.AndroidUtils;
-import org.briarproject.bramble.util.StringUtils;
-
-import java.io.Closeable;
-import java.io.IOException;
-import java.security.SecureRandom;
-import java.util.Collection;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.UUID;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.ACTION_STATE_CHANGED;
-import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
-import static android.bluetooth.BluetoothAdapter.EXTRA_STATE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
-import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
-import static android.bluetooth.BluetoothAdapter.STATE_OFF;
-import static android.bluetooth.BluetoothAdapter.STATE_ON;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
-import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
-
-@MethodsNotNullByDefault
-@ParametersNotNullByDefault
-class DroidtoothPlugin implements DuplexPlugin, EventListener {
-
-	private static final Logger LOG =
-			Logger.getLogger(DroidtoothPlugin.class.getName());
-
-	private final Executor ioExecutor;
-	private final AndroidExecutor androidExecutor;
-	private final Context appContext;
-	private final SecureRandom secureRandom;
-	private final Backoff backoff;
-	private final DuplexPluginCallback callback;
-	private final int maxLatency;
-	private final AtomicBoolean used = new AtomicBoolean(false);
-
-	private volatile boolean running = false;
-	private volatile boolean wasEnabledByUs = false;
-	private volatile BluetoothStateReceiver receiver = null;
-	private volatile BluetoothServerSocket socket = null;
-
-	// Non-null if the plugin started successfully
-	private volatile BluetoothAdapter adapter = null;
-
-	DroidtoothPlugin(Executor ioExecutor, AndroidExecutor androidExecutor,
-			Context appContext, SecureRandom secureRandom, Backoff backoff,
-			DuplexPluginCallback callback, int maxLatency) {
-		this.ioExecutor = ioExecutor;
-		this.androidExecutor = androidExecutor;
-		this.appContext = appContext;
-		this.secureRandom = secureRandom;
-		this.backoff = backoff;
-		this.callback = callback;
-		this.maxLatency = maxLatency;
-	}
-
-	@Override
-	public TransportId getId() {
-		return ID;
-	}
-
-	@Override
-	public int getMaxLatency() {
-		return maxLatency;
-	}
-
-	@Override
-	public int getMaxIdleTime() {
-		// Bluetooth detects dead connections so we don't need keepalives
-		return Integer.MAX_VALUE;
-	}
-
-	@Override
-	public void start() throws PluginException {
-		if (used.getAndSet(true)) throw new IllegalStateException();
-		// BluetoothAdapter.getDefaultAdapter() must be called on a thread
-		// with a message queue, so submit it to the AndroidExecutor
-		try {
-			adapter = androidExecutor.runOnBackgroundThread(
-					BluetoothAdapter::getDefaultAdapter).get();
-		} catch (InterruptedException e) {
-			Thread.currentThread().interrupt();
-			LOG.warning("Interrupted while getting BluetoothAdapter");
-			throw new PluginException(e);
-		} catch (ExecutionException e) {
-			throw new PluginException(e);
-		}
-		if (adapter == null) {
-			LOG.info("Bluetooth is not supported");
-			throw new PluginException();
-		}
-		running = true;
-		// Listen for changes to the Bluetooth state
-		IntentFilter filter = new IntentFilter();
-		filter.addAction(ACTION_STATE_CHANGED);
-		filter.addAction(ACTION_SCAN_MODE_CHANGED);
-		receiver = new BluetoothStateReceiver();
-		appContext.registerReceiver(receiver, filter);
-		// If Bluetooth is enabled, bind a socket
-		if (adapter.isEnabled()) {
-			bind();
-		} else {
-			// Enable Bluetooth if settings allow
-			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, false)) {
-				enableAdapter();
-			} else {
-				LOG.info("Not enabling Bluetooth");
-			}
-		}
-	}
-
-	private void bind() {
-		ioExecutor.execute(() -> {
-			if (!isRunning()) return;
-			String address = AndroidUtils.getBluetoothAddress(appContext,
-					adapter);
-			if (LOG.isLoggable(INFO))
-				LOG.info("Local address " + scrubMacAddress(address));
-			if (!StringUtils.isNullOrEmpty(address)) {
-				// Advertise the Bluetooth address to contacts
-				TransportProperties p = new TransportProperties();
-				p.put(PROP_ADDRESS, address);
-				callback.mergeLocalProperties(p);
-			}
-			// Bind a server socket to accept connections from contacts
-			BluetoothServerSocket ss;
-			try {
-				ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
-						"RFCOMM", getUuid());
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				return;
-			}
-			if (!isRunning()) {
-				tryToClose(ss);
-				return;
-			}
-			LOG.info("Socket bound");
-			socket = ss;
-			backoff.reset();
-			callback.transportEnabled();
-			acceptContactConnections();
-		});
-	}
-
-	private UUID getUuid() {
-		String uuid = callback.getLocalProperties().get(PROP_UUID);
-		if (uuid == null) {
-			byte[] random = new byte[UUID_BYTES];
-			secureRandom.nextBytes(random);
-			uuid = UUID.nameUUIDFromBytes(random).toString();
-			TransportProperties p = new TransportProperties();
-			p.put(PROP_UUID, uuid);
-			callback.mergeLocalProperties(p);
-		}
-		return UUID.fromString(uuid);
-	}
-
-	private void tryToClose(@Nullable BluetoothServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		} finally {
-			callback.transportDisabled();
-		}
-	}
-
-	private void acceptContactConnections() {
-		while (isRunning()) {
-			BluetoothSocket s;
-			try {
-				s = socket.accept();
-			} catch (IOException e) {
-				// This is expected when the socket is closed
-				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
-				return;
-			}
-			if (LOG.isLoggable(INFO)) {
-				String address = s.getRemoteDevice().getAddress();
-				LOG.info("Connection from " + scrubMacAddress(address));
-			}
-			backoff.reset();
-			callback.incomingConnectionCreated(wrapSocket(s));
-		}
-	}
-
-	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
-		return new DroidtoothTransportConnection(this, s);
-	}
-
-	private void enableAdapter() {
-		if (adapter != null && !adapter.isEnabled()) {
-			if (adapter.enable()) {
-				LOG.info("Enabling Bluetooth");
-				wasEnabledByUs = true;
-			} else {
-				LOG.info("Could not enable Bluetooth");
-			}
-		}
-	}
-
-	@Override
-	public void stop() {
-		running = false;
-		if (receiver != null) appContext.unregisterReceiver(receiver);
-		tryToClose(socket);
-		disableAdapter();
-	}
-
-	private void disableAdapter() {
-		if (adapter != null && adapter.isEnabled() && wasEnabledByUs) {
-			if (adapter.disable()) LOG.info("Disabling Bluetooth");
-			else LOG.info("Could not disable Bluetooth");
-		}
-	}
-
-	@Override
-	public boolean isRunning() {
-		return running && adapter != null && adapter.isEnabled();
-	}
-
-	@Override
-	public boolean shouldPoll() {
-		return true;
-	}
-
-	@Override
-	public int getPollingInterval() {
-		return backoff.getPollingInterval();
-	}
-
-	@Override
-	public void poll(Collection<ContactId> connected) {
-		if (!isRunning()) return;
-		backoff.increment();
-		// Try to connect to known devices in parallel
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (connected.contains(c)) continue;
-			String address = e.getValue().get(PROP_ADDRESS);
-			if (StringUtils.isNullOrEmpty(address)) continue;
-			String uuid = e.getValue().get(PROP_UUID);
-			if (StringUtils.isNullOrEmpty(uuid)) continue;
-			ioExecutor.execute(() -> {
-				if (!running) return;
-				BluetoothSocket s = connect(address, uuid);
-				if (s != null) {
-					backoff.reset();
-					callback.outgoingConnectionCreated(c, wrapSocket(s));
-				}
-			});
-		}
-	}
-
-	@Nullable
-	private BluetoothSocket connect(String address, String uuid) {
-		// Validate the address
-		if (!BluetoothAdapter.checkBluetoothAddress(address)) {
-			if (LOG.isLoggable(WARNING))
-				// not scrubbing here to be able to figure out the problem
-				LOG.warning("Invalid address " + address);
-			return null;
-		}
-		// Validate the UUID
-		UUID u;
-		try {
-			u = UUID.fromString(uuid);
-		} catch (IllegalArgumentException e) {
-			if (LOG.isLoggable(WARNING)) LOG.warning("Invalid UUID " + uuid);
-			return null;
-		}
-		// Try to connect
-		BluetoothDevice d = adapter.getRemoteDevice(address);
-		BluetoothSocket s = null;
-		try {
-			s = d.createInsecureRfcommSocketToServiceRecord(u);
-			if (LOG.isLoggable(INFO))
-				LOG.info("Connecting to " + scrubMacAddress(address));
-			s.connect();
-			if (LOG.isLoggable(INFO))
-				LOG.info("Connected to " + scrubMacAddress(address));
-			return s;
-		} catch (IOException e) {
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Failed to connect to " + scrubMacAddress(address)
-						+ ": " + e);
-			}
-			tryToClose(s);
-			return null;
-		}
-	}
-
-	private void tryToClose(@Nullable Closeable c) {
-		try {
-			if (c != null) c.close();
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-	}
-
-	@Override
-	public DuplexTransportConnection createConnection(ContactId c) {
-		if (!isRunning()) return null;
-		TransportProperties p = callback.getRemoteProperties(c);
-		String address = p.get(PROP_ADDRESS);
-		if (StringUtils.isNullOrEmpty(address)) return null;
-		String uuid = p.get(PROP_UUID);
-		if (StringUtils.isNullOrEmpty(uuid)) return null;
-		BluetoothSocket s = connect(address, uuid);
-		if (s == null) return null;
-		return new DroidtoothTransportConnection(this, s);
-	}
-
-	@Override
-	public boolean supportsKeyAgreement() {
-		return true;
-	}
-
-	@Override
-	public KeyAgreementListener createKeyAgreementListener(byte[] commitment) {
-		if (!isRunning()) return null;
-		// There's no point listening if we can't discover our own address
-		String address = AndroidUtils.getBluetoothAddress(appContext, adapter);
-		if (address.isEmpty()) return null;
-		// No truncation necessary because COMMIT_LENGTH = 16
-		UUID uuid = UUID.nameUUIDFromBytes(commitment);
-		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
-		// Bind a server socket for receiving key agreement connections
-		BluetoothServerSocket ss;
-		try {
-			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
-					"RFCOMM", uuid);
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			return null;
-		}
-		BdfList descriptor = new BdfList();
-		descriptor.add(TRANSPORT_ID_BLUETOOTH);
-		descriptor.add(StringUtils.macToBytes(address));
-		return new BluetoothKeyAgreementListener(descriptor, ss);
-	}
-
-	@Override
-	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor, long timeout) {
-		if (!isRunning()) return null;
-		String address;
-		try {
-			address = parseAddress(descriptor);
-		} catch (FormatException e) {
-			LOG.info("Invalid address in key agreement descriptor");
-			return null;
-		}
-		// No truncation necessary because COMMIT_LENGTH = 16
-		UUID uuid = UUID.nameUUIDFromBytes(commitment);
-		if (LOG.isLoggable(INFO))
-			LOG.info("Connecting to key agreement UUID " + uuid);
-		BluetoothSocket s = connect(address, uuid.toString());
-		if (s == null) return null;
-		return new DroidtoothTransportConnection(this, s);
-	}
-
-	private String parseAddress(BdfList descriptor) throws FormatException {
-		byte[] mac = descriptor.getRaw(1);
-		if (mac.length != 6) throw new FormatException();
-		return StringUtils.macToString(mac);
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof EnableBluetoothEvent) {
-			enableAdapterAsync();
-		} else if (e instanceof DisableBluetoothEvent) {
-			disableAdapterAsync();
-		}
-	}
-
-	private void enableAdapterAsync() {
-		ioExecutor.execute(this::enableAdapter);
-	}
-
-	private void disableAdapterAsync() {
-		ioExecutor.execute(this::disableAdapter);
-	}
-
-	private class BluetoothStateReceiver extends BroadcastReceiver {
-
-		@Override
-		public void onReceive(Context ctx, Intent intent) {
-			int state = intent.getIntExtra(EXTRA_STATE, 0);
-			if (state == STATE_ON) {
-				LOG.info("Bluetooth enabled");
-				bind();
-			} else if (state == STATE_OFF) {
-				LOG.info("Bluetooth disabled");
-				tryToClose(socket);
-			}
-			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
-			if (scanMode == SCAN_MODE_NONE) {
-				LOG.info("Scan mode: None");
-			} else if (scanMode == SCAN_MODE_CONNECTABLE) {
-				LOG.info("Scan mode: Connectable");
-			} else if (scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE) {
-				LOG.info("Scan mode: Discoverable");
-			}
-		}
-	}
-
-	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
-
-		private final BluetoothServerSocket ss;
-
-		private BluetoothKeyAgreementListener(BdfList descriptor,
-				BluetoothServerSocket ss) {
-			super(descriptor);
-			this.ss = ss;
-		}
-
-		@Override
-		public Callable<KeyAgreementConnection> listen() {
-			return () -> {
-				BluetoothSocket s = ss.accept();
-				if (LOG.isLoggable(INFO))
-					LOG.info(ID.getString() + ": Incoming connection");
-				return new KeyAgreementConnection(
-						new DroidtoothTransportConnection(
-								DroidtoothPlugin.this, s), ID);
-			};
-		}
-
-		@Override
-		public void close() {
-			try {
-				ss.close();
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			}
-		}
-	}
-}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java
@@ -5,37 +5,84 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
+import android.net.Network;
 import android.net.NetworkInfo;
+import android.net.wifi.WifiInfo;
+import android.net.wifi.WifiManager;

 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;

+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+import java.net.UnknownHostException;
+import java.util.Collection;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;

 import javax.annotation.Nullable;
+import javax.net.SocketFactory;

 import static android.content.Context.CONNECTIVITY_SERVICE;
+import static android.content.Context.WIFI_SERVICE;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.net.wifi.WifiManager.EXTRA_WIFI_STATE;
+import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static java.util.concurrent.TimeUnit.SECONDS;

@NotNullByDefault
 class AndroidLanTcpPlugin extends LanTcpPlugin {

+	// See android.net.wifi.WifiManager
+	private static final String WIFI_AP_STATE_CHANGED_ACTION =
+			"android.net.wifi.WIFI_AP_STATE_CHANGED";
+	private static final int WIFI_AP_STATE_ENABLED = 13;
+
+	private static final byte[] WIFI_AP_ADDRESS_BYTES =
+			{(byte) 192, (byte) 168, 43, 1};
+	private static final InetAddress WIFI_AP_ADDRESS;
+
 	private static final Logger LOG =
 			Logger.getLogger(AndroidLanTcpPlugin.class.getName());

+	static {
+		try {
+			WIFI_AP_ADDRESS = InetAddress.getByAddress(WIFI_AP_ADDRESS_BYTES);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if the address has an illegal length
+			throw new AssertionError(e);
+		}
+	}
+
+	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
+	private final ConnectivityManager connectivityManager;
+	@Nullable
+	private final WifiManager wifiManager;

 	@Nullable
 	private volatile BroadcastReceiver networkStateReceiver = null;
+	private volatile SocketFactory socketFactory;

-	AndroidLanTcpPlugin(Executor ioExecutor, Backoff backoff,
-			Context appContext, DuplexPluginCallback callback, int maxLatency,
-			int maxIdleTime) {
+	AndroidLanTcpPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+			Backoff backoff, Context appContext, DuplexPluginCallback callback,
+			int maxLatency, int maxIdleTime) {
 		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
+		this.scheduler = scheduler;
 		this.appContext = appContext;
+		ConnectivityManager connectivityManager = (ConnectivityManager)
+				appContext.getSystemService(CONNECTIVITY_SERVICE);
+		if (connectivityManager == null) throw new AssertionError();
+		this.connectivityManager = connectivityManager;
+		wifiManager = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		socketFactory = SocketFactory.getDefault();
 	}

 	@Override
@@ -44,7 +91,9 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		running = true;
 		// Register to receive network status events
 		networkStateReceiver = new NetworkStateReceiver();
-		IntentFilter filter = new IntentFilter(CONNECTIVITY_ACTION);
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(CONNECTIVITY_ACTION);
+		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
 		appContext.registerReceiver(networkStateReceiver, filter);
 	}

@@ -56,21 +105,92 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		tryToClose(socket);
 	}

+	@Override
+	protected Socket createSocket() throws IOException {
+		return socketFactory.createSocket();
+	}
+
+	@Override
+	protected Collection<InetAddress> getLocalIpAddresses() {
+		// If the device doesn't have wifi, don't open any sockets
+		if (wifiManager == null) return emptyList();
+		// If we're connected to a wifi network, use that network
+		WifiInfo info = wifiManager.getConnectionInfo();
+		if (info != null && info.getIpAddress() != 0)
+			return singletonList(intToInetAddress(info.getIpAddress()));
+		// If we're running an access point, return its address
+		if (super.getLocalIpAddresses().contains(WIFI_AP_ADDRESS))
+				return singletonList(WIFI_AP_ADDRESS);
+		// No suitable addresses
+		return emptyList();
+	}
+
+	private InetAddress intToInetAddress(int ip) {
+		byte[] ipBytes = new byte[4];
+		ipBytes[0] = (byte) (ip & 0xFF);
+		ipBytes[1] = (byte) ((ip >> 8) & 0xFF);
+		ipBytes[2] = (byte) ((ip >> 16) & 0xFF);
+		ipBytes[3] = (byte) ((ip >> 24) & 0xFF);
+		try {
+			return InetAddress.getByAddress(ipBytes);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if address has illegal length
+			throw new AssertionError(e);
+		}
+	}
+
+	// On API 21 and later, a socket that is not created with the wifi
+	// network's socket factory may try to connect via another network
+	private SocketFactory getSocketFactory() {
+		if (SDK_INT < 21) return SocketFactory.getDefault();
+		for (Network net : connectivityManager.getAllNetworks()) {
+			NetworkInfo info = connectivityManager.getNetworkInfo(net);
+			if (info != null && info.getType() == TYPE_WIFI)
+				return net.getSocketFactory();
+		}
+		LOG.warning("Could not find suitable socket factory");
+		return SocketFactory.getDefault();
+	}
+
 	private class NetworkStateReceiver extends BroadcastReceiver {

 		@Override
 		public void onReceive(Context ctx, Intent i) {
 			if (!running) return;
-			Object o = ctx.getSystemService(CONNECTIVITY_SERVICE);
-			ConnectivityManager cm = (ConnectivityManager) o;
-			NetworkInfo net = cm.getActiveNetworkInfo();
-			if (net != null && net.getType() == TYPE_WIFI && net.isConnected()) {
-				LOG.info("Connected to Wi-Fi");
-				if (socket == null || socket.isClosed()) bind();
+			if (isApEnabledEvent(i)) {
+				// The state change may be broadcast before the AP address is
+				// visible, so delay handling the event
+				scheduler.schedule(this::handleConnectivityChange, 1, SECONDS);
 			} else {
-				LOG.info("Not connected to Wi-Fi");
-				tryToClose(socket);
+				handleConnectivityChange();
 			}
 		}
+
+		private void handleConnectivityChange() {
+			if (!running) return;
+			Collection<InetAddress> addrs = getLocalIpAddresses();
+			if (addrs.contains(WIFI_AP_ADDRESS)) {
+				LOG.info("Providing wifi hotspot");
+				// There's no corresponding Network object and thus no way
+				// to get a suitable socket factory, so we won't be able to
+				// make outgoing connections on API 21+ if another network
+				// has internet access
+				socketFactory = SocketFactory.getDefault();
+				if (socket == null || socket.isClosed()) bind();
+			} else if (addrs.isEmpty()) {
+				LOG.info("Not connected to wifi");
+				socketFactory = SocketFactory.getDefault();
+				tryToClose(socket);
+			} else {
+				LOG.info("Connected to wifi");
+				socketFactory = getSocketFactory();
+				if (socket == null || socket.isClosed()) bind();
+			}
+		}
+
+		private boolean isApEnabledEvent(Intent i) {
+			return WIFI_AP_STATE_CHANGED_ACTION.equals(i.getAction()) &&
+					i.getIntExtra(EXTRA_WIFI_STATE, 0) == WIFI_AP_STATE_ENABLED;
+		}
 	}
 }
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java
@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;

 import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;

 import javax.annotation.concurrent.Immutable;

@@ -27,12 +28,15 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;

 	private final Executor ioExecutor;
+	private final ScheduledExecutorService scheduler;
 	private final BackoffFactory backoffFactory;
 	private final Context appContext;

 	public AndroidLanTcpPluginFactory(Executor ioExecutor,
-			BackoffFactory backoffFactory, Context appContext) {
+			ScheduledExecutorService scheduler, BackoffFactory backoffFactory,
+			Context appContext) {
 		this.ioExecutor = ioExecutor;
+		this.scheduler = scheduler;
 		this.backoffFactory = backoffFactory;
 		this.appContext = appContext;
 	}
@@ -51,7 +55,7 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		return new AndroidLanTcpPlugin(ioExecutor, backoff, appContext,
-				callback, MAX_LATENCY, MAX_IDLE_TIME);
+		return new AndroidLanTcpPlugin(ioExecutor, scheduler, backoff,
+				appContext, callback, MAX_LATENCY, MAX_IDLE_TIME);
 	}
 }
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProvider.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProvider.java
@@ -0,0 +1,30 @@
+package org.briarproject.bramble.plugin.tor;
+
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+
+import java.util.List;
+
+public interface CircumventionProvider {
+
+	/**
+	 * Countries where Tor is blocked, i.e. vanilla Tor connection won't work.
+	 *
+	 * See https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
+	 * and https://trac.torproject.org/projects/tor/wiki/doc/OONI/censorshipwiki
+	 */
+	String[] BLOCKED = {"CN", "IR", "EG", "BY", "TR", "SY", "VE"};
+
+	/**
+	 * Countries where vanilla bridge connection are likely to work.
+	 * Should be a subset of {@link #BLOCKED}.
+	 */
+	String[] BRIDGES = { "EG", "BY", "TR", "SY", "VE" };
+
+	boolean isTorProbablyBlocked(String countryCode);
+
+	boolean doBridgesWork(String countryCode);
+
+	@IoExecutor
+	List<String> getBridges();
+
+}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProviderImpl.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/CircumventionProviderImpl.java
@@ -0,0 +1,68 @@
+package org.briarproject.bramble.plugin.tor;
+
+import android.content.Context;
+import android.content.res.Resources;
+
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Scanner;
+import java.util.Set;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+public class CircumventionProviderImpl implements CircumventionProvider {
+
+	private final static String BRIDGE_FILE_NAME = "bridges";
+
+	private final Context ctx;
+	@Nullable
+	private volatile List<String> bridges = null;
+
+	@Inject
+	public CircumventionProviderImpl(Context ctx) {
+		this.ctx = ctx;
+	}
+
+	private static final Set<String> BLOCKED_IN_COUNTRIES =
+			new HashSet<>(Arrays.asList(BLOCKED));
+	private static final Set<String> BRIDGES_WORK_IN_COUNTRIES =
+			new HashSet<>(Arrays.asList(BRIDGES));
+
+	@Override
+	public boolean isTorProbablyBlocked(String countryCode) {
+		return BLOCKED_IN_COUNTRIES.contains(countryCode);
+	}
+
+	@Override
+	public boolean doBridgesWork(String countryCode) {
+		return BRIDGES_WORK_IN_COUNTRIES.contains(countryCode);
+	}
+
+	@Override
+	@IoExecutor
+	public List<String> getBridges() {
+		if (this.bridges != null) return this.bridges;
+
+		Resources res = ctx.getResources();
+		int resId = res.getIdentifier(BRIDGE_FILE_NAME, "raw",
+				ctx.getPackageName());
+		InputStream is = ctx.getResources().openRawResource(resId);
+		Scanner scanner = new Scanner(is);
+
+		List<String> bridges = new ArrayList<>();
+		while (scanner.hasNextLine()) {
+			String line = scanner.nextLine();
+			if (!line.startsWith("#")) bridges.add(line);
+		}
+		scanner.close();
+		this.bridges = bridges;
+		return bridges;
+	}
+
+}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorNetworkMetadata.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorNetworkMetadata.java
@@ -1,18 +0,0 @@
-package org.briarproject.bramble.plugin.tor;
-
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Set;
-
-class TorNetworkMetadata {
-
-	// See https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
-	// and https://trac.torproject.org/projects/tor/wiki/doc/OONI/censorshipwiki
-	// TODO: get a more complete list
-	private static final Set<String> BLOCKED_IN_COUNTRIES =
-			new HashSet<>(Arrays.asList("CN", "IR", "SY", "ZZ"));
-
-	static boolean isTorProbablyBlocked(String countryCode) {
-		return BLOCKED_IN_COUNTRIES.contains(countryCode);
-	}
-}
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java
@@ -10,12 +10,12 @@ import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.res.Resources;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
-import android.os.FileObserver;
 import android.os.PowerManager;

 import net.freehaven.tor.control.EventHandler;
 import net.freehaven.tor.control.TorControlConnection;

+import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
@@ -31,12 +31,12 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.reporting.DevReporter;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.util.AndroidUtils;
 import org.briarproject.bramble.util.IoUtils;
+import org.briarproject.bramble.util.RenewableWakeLock;
 import org.briarproject.bramble.util.StringUtils;

 import java.io.Closeable;
@@ -50,6 +50,7 @@ import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -57,9 +58,11 @@ import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Scanner;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
 import java.util.zip.ZipInputStream;
@@ -70,14 +73,19 @@ import javax.net.SocketFactory;
 import static android.content.Context.CONNECTIVITY_SERVICE;
 import static android.content.Context.MODE_PRIVATE;
 import static android.content.Context.POWER_SERVICE;
+import static android.content.Intent.ACTION_SCREEN_OFF;
+import static android.content.Intent.ACTION_SCREEN_ON;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
 import static android.os.PowerManager.PARTIAL_WAKE_LOCK;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static net.freehaven.tor.control.TorControlCommands.HS_ADDRESS;
 import static net.freehaven.tor.control.TorControlCommands.HS_PRIVKEY;
+import static org.briarproject.bramble.PowerTestingConstants.USE_TOR_WAKE_LOCK;
 import static org.briarproject.bramble.api.plugin.TorConstants.CONTROL_PORT;
 import static org.briarproject.bramble.api.plugin.TorConstants.ID;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
@@ -86,6 +94,7 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_WIFI;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
 import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION;
+import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubOnion;

@MethodsNotNullByDefault
@@ -96,24 +105,31 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			"CIRC", "ORCONN", "HS_DESC", "NOTICE", "WARN", "ERR"
 	};
 	private static final String OWNER = "__OwningControllerProcess";
-	private static final int COOKIE_TIMEOUT = 3000; // Milliseconds
+	private static final int COOKIE_TIMEOUT_MS = 3000;
+	private static final int COOKIE_POLLING_INTERVAL_MS = 200;
 	private static final Pattern ONION = Pattern.compile("[a-z2-7]{16}");
+	// This tag may prevent Huawei's power manager from killing us
+	private static final String WAKE_LOCK_TAG = "LocationManagerService";
 	private static final Logger LOG =
 			Logger.getLogger(TorPlugin.class.getName());

-	private final Executor ioExecutor;
+	private final Executor ioExecutor, connectionStatusExecutor;
+	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
 	private final LocationUtils locationUtils;
-	private final DevReporter reporter;
 	private final SocketFactory torSocketFactory;
+	private final Clock clock;
 	private final Backoff backoff;
 	private final DuplexPluginCallback callback;
 	private final String architecture;
+	private final CircumventionProvider circumventionProvider;
 	private final int maxLatency, maxIdleTime, socketTimeout;
 	private final ConnectionStatus connectionStatus;
 	private final File torDirectory, torFile, geoIpFile, configFile;
 	private final File doneFile, cookieFile;
-	private final PowerManager.WakeLock wakeLock;
+	private final RenewableWakeLock wakeLock;
+	private final AtomicReference<Future<?>> connectivityCheck =
+			new AtomicReference<>();
 	private final AtomicBoolean used = new AtomicBoolean(false);

 	private volatile boolean running = false;
@@ -122,19 +138,21 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private volatile TorControlConnection controlConnection = null;
 	private volatile BroadcastReceiver networkStateReceiver = null;

-	TorPlugin(Executor ioExecutor, Context appContext,
-			LocationUtils locationUtils, DevReporter reporter,
-			SocketFactory torSocketFactory, Backoff backoff,
-			DuplexPluginCallback callback, String architecture, int maxLatency,
-			int maxIdleTime) {
+	TorPlugin(Executor ioExecutor, ScheduledExecutorService scheduler,
+			Context appContext, LocationUtils locationUtils,
+			SocketFactory torSocketFactory, Clock clock, Backoff backoff,
+			DuplexPluginCallback callback, String architecture,
+			CircumventionProvider circumventionProvider, int maxLatency, int maxIdleTime) {
 		this.ioExecutor = ioExecutor;
+		this.scheduler = scheduler;
 		this.appContext = appContext;
 		this.locationUtils = locationUtils;
-		this.reporter = reporter;
 		this.torSocketFactory = torSocketFactory;
+		this.clock = clock;
 		this.backoff = backoff;
 		this.callback = callback;
 		this.architecture = architecture;
+		this.circumventionProvider = circumventionProvider;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
 		if (maxIdleTime > Integer.MAX_VALUE / 2)
@@ -147,11 +165,13 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		configFile = new File(torDirectory, "torrc");
 		doneFile = new File(torDirectory, "done");
 		cookieFile = new File(torDirectory, ".tor/control_auth_cookie");
-		Object o = appContext.getSystemService(POWER_SERVICE);
-		PowerManager pm = (PowerManager) o;
-		// This tag will prevent Huawei's powermanager from killing us.
-		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "LocationManagerService");
-		wakeLock.setReferenceCounted(false);
+		// Don't execute more than one connection status check at a time
+		connectionStatusExecutor = new PoliteExecutor("TorPlugin",
+				ioExecutor, 1);
+		PowerManager pm = (PowerManager)
+				appContext.getSystemService(POWER_SERVICE);
+		wakeLock = new RenewableWakeLock(pm, scheduler, PARTIAL_WAKE_LOCK,
+				WAKE_LOCK_TAG, 1, MINUTES);
 	}

 	@Override
@@ -174,18 +194,10 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (used.getAndSet(true)) throw new IllegalStateException();
 		// Install or update the assets if necessary
 		if (!assetsAreUpToDate()) installAssets();
-		LOG.info("Starting Tor");
-		// Watch for the auth cookie file being updated
-		try {
-			cookieFile.getParentFile().mkdirs();
-			cookieFile.createNewFile();
-		} catch (IOException e) {
-			throw new PluginException(e);
-		}
-		CountDownLatch latch = new CountDownLatch(1);
-		FileObserver obs = new WriteObserver(cookieFile, latch);
-		obs.startWatching();
+		if (cookieFile.exists() && !cookieFile.delete())
+			LOG.warning("Old auth cookie not deleted");
 		// Start a new Tor process
+		LOG.info("Starting Tor");
 		String torPath = torFile.getAbsolutePath();
 		String configPath = configFile.getAbsolutePath();
 		String pid = String.valueOf(android.os.Process.myPid());
@@ -204,11 +216,11 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (LOG.isLoggable(INFO)) {
 			Scanner stdout = new Scanner(torProcess.getInputStream());
 			Scanner stderr = new Scanner(torProcess.getErrorStream());
-			while (stdout.hasNextLine() || stderr.hasNextLine()){
-				if(stdout.hasNextLine()) {
+			while (stdout.hasNextLine() || stderr.hasNextLine()) {
+				if (stdout.hasNextLine()) {
 					LOG.info(stdout.nextLine());
 				}
-				if(stderr.hasNextLine()){
+				if (stderr.hasNextLine()) {
 					LOG.info(stderr.nextLine());
 				}
 			}
@@ -224,11 +236,16 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				throw new PluginException();
 			}
 			// Wait for the auth cookie file to be created/updated
-			if (!latch.await(COOKIE_TIMEOUT, MILLISECONDS)) {
-				LOG.warning("Auth cookie not created");
-				if (LOG.isLoggable(INFO)) listFiles(torDirectory);
-				throw new PluginException();
+			long start = clock.currentTimeMillis();
+			while (cookieFile.length() < 32) {
+				if (clock.currentTimeMillis() - start > COOKIE_TIMEOUT_MS) {
+					LOG.warning("Auth cookie not created");
+					if (LOG.isLoggable(INFO)) listFiles(torDirectory);
+					throw new PluginException();
+				}
+				Thread.sleep(COOKIE_POLLING_INTERVAL_MS);
 			}
+			LOG.info("Auth cookie created");
 		} catch (InterruptedException e) {
 			LOG.warning("Interrupted while starting Tor");
 			Thread.currentThread().interrupt();
@@ -257,7 +274,11 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 		// Register to receive network status events
 		networkStateReceiver = new NetworkStateReceiver();
-		IntentFilter filter = new IntentFilter(CONNECTIVITY_ACTION);
+		IntentFilter filter = new IntentFilter();
+		filter.addAction(CONNECTIVITY_ACTION);
+		filter.addAction(ACTION_SCREEN_ON);
+		filter.addAction(ACTION_SCREEN_OFF);
+		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
 		appContext.registerReceiver(networkStateReceiver, filter);
 		// Bind a server socket to receive incoming hidden service connections
 		bind();
@@ -318,7 +339,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		return zin;
 	}

-	private InputStream getConfigInputStream() throws IOException {
+	private InputStream getConfigInputStream() {
 		int resId = getResourceId("torrc");
 		return appContext.getResources().openRawResource(resId);
 	}
@@ -332,7 +353,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		try {
 			if (c != null) c.close();
 		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			logException(LOG, WARNING, e);
 		}
 	}

@@ -340,7 +361,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		try {
 			if (s != null) s.close();
 		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			logException(LOG, WARNING, e);
 		}
 	}

@@ -349,7 +370,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			File[] children = f.listFiles();
 			if (children != null) for (File child : children) listFiles(child);
 		} else {
-			LOG.info(f.getAbsolutePath());
+			LOG.info(f.getAbsolutePath() + " " + f.length());
 		}
 	}

@@ -369,14 +390,6 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}

-	private void sendDevReports() {
-		ioExecutor.execute(() -> {
-			// TODO: Trigger this with a TransportEnabledEvent
-			File reportDir = AndroidUtils.getReportDir(appContext);
-			reporter.sendReports(reportDir);
-		});
-	}
-
 	private void bind() {
 		ioExecutor.execute(() -> {
 			// If there's already a port number stored in config, reuse it
@@ -390,7 +403,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				ss = new ServerSocket();
 				ss.bind(new InetSocketAddress("127.0.0.1", port));
 			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				logException(LOG, WARNING, e);
 				tryToClose(ss);
 				return;
 			}
@@ -416,7 +429,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		try {
 			if (ss != null) ss.close();
 		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			logException(LOG, WARNING, e);
 		} finally {
 			callback.transportDisabled();
 		}
@@ -435,7 +448,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				response = controlConnection.addOnion(portLines);
 			else response = controlConnection.addOnion(privKey, portLines);
 		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			logException(LOG, WARNING, e);
 			return;
 		}
 		if (!response.containsKey(HS_ADDRESS)) {
@@ -481,17 +494,28 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {

 	private void enableNetwork(boolean enable) throws IOException {
 		if (!running) return;
-		if (enable) wakeLock.acquire();
+		if (enable && USE_TOR_WAKE_LOCK) wakeLock.acquire();
 		connectionStatus.enableNetwork(enable);
 		controlConnection.setConf("DisableNetwork", enable ? "0" : "1");
 		if (!enable) {
 			callback.transportDisabled();
-			wakeLock.release();
+			if (USE_TOR_WAKE_LOCK) wakeLock.release();
+		}
+	}
+
+	private void enableBridges(boolean enable) throws IOException {
+		if (enable) {
+			Collection<String> conf = new ArrayList<>();
+			conf.add("UseBridges 1");
+			conf.addAll(circumventionProvider.getBridges());
+			controlConnection.setConf(conf);
+		} else {
+			controlConnection.setConf("UseBridges", "0");
 		}
 	}

 	@Override
-	public void stop() throws PluginException {
+	public void stop() {
 		running = false;
 		tryToClose(socket);
 		if (networkStateReceiver != null)
@@ -503,10 +527,10 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				controlConnection.shutdownTor("TERM");
 				controlSocket.close();
 			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				logException(LOG, WARNING, e);
 			}
 		}
-		wakeLock.release();
+		if (USE_TOR_WAKE_LOCK) wakeLock.release();
 	}

 	@Override
@@ -525,20 +549,16 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}

 	@Override
-	public void poll(Collection<ContactId> connected) {
+	public void poll(Map<ContactId, TransportProperties> contacts) {
 		if (!isRunning()) return;
 		backoff.increment();
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (!connected.contains(c)) connectAndCallBack(c, e.getValue());
+		for (Entry<ContactId, TransportProperties> e : contacts.entrySet()) {
+			connectAndCallBack(e.getKey(), e.getValue());
 		}
 	}

 	private void connectAndCallBack(ContactId c, TransportProperties p) {
 		ioExecutor.execute(() -> {
-			if (!isRunning()) return;
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();
@@ -548,13 +568,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}

 	@Override
-	public DuplexTransportConnection createConnection(ContactId c) {
+	public DuplexTransportConnection createConnection(TransportProperties p) {
 		if (!isRunning()) return null;
-		return createConnection(callback.getRemoteProperties(c));
-	}
-
-	@Nullable
-	private DuplexTransportConnection createConnection(TransportProperties p) {
 		String onion = p.get(PROP_ONION);
 		if (StringUtils.isNullOrEmpty(onion)) return null;
 		if (!ONION.matcher(onion).matches()) {
@@ -594,7 +609,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {

 	@Override
 	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor, long timeout) {
+			byte[] commitment, BdfList descriptor) {
 		throw new UnsupportedOperationException();
 	}

@@ -604,10 +619,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				connectionStatus.getAndSetCircuitBuilt()) {
 			LOG.info("First circuit built");
 			backoff.reset();
-			if (isRunning()) {
-				sendDevReports();
-				callback.transportEnabled();
-			}
+			if (isRunning()) callback.transportEnabled();
 		}
 	}

@@ -618,6 +630,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void orConnStatus(String status, String orName) {
 		if (LOG.isLoggable(INFO)) LOG.info("OR connection " + status);
+		if (status.equals("CLOSED") || status.equals("FAILED"))
+			updateConnectionStatus(); // Check whether we've lost connectivity
 	}

 	@Override
@@ -634,10 +648,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (severity.equals("NOTICE") && msg.startsWith("Bootstrapped 100%")) {
 			connectionStatus.setBootstrapped();
 			backoff.reset();
-			if (isRunning()) {
-				sendDevReports();
-				callback.transportEnabled();
-			}
+			if (isRunning()) callback.transportEnabled();
 		}
 	}

@@ -647,22 +658,6 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			LOG.info("Descriptor uploaded");
 	}

-	private static class WriteObserver extends FileObserver {
-
-		private final CountDownLatch latch;
-
-		private WriteObserver(File file, CountDownLatch latch) {
-			super(file.getAbsolutePath(), CLOSE_WRITE);
-			this.latch = latch;
-		}
-
-		@Override
-		public void onEvent(int event, String path) {
-			stopWatching();
-			latch.countDown();
-		}
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof SettingsUpdatedEvent) {
@@ -675,17 +670,16 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}

 	private void updateConnectionStatus() {
-		ioExecutor.execute(() -> {
+		connectionStatusExecutor.execute(() -> {
 			if (!running) return;
-
 			Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
 			ConnectivityManager cm = (ConnectivityManager) o;
 			NetworkInfo net = cm.getActiveNetworkInfo();
 			boolean online = net != null && net.isConnected();
 			boolean wifi = online && net.getType() == TYPE_WIFI;
 			String country = locationUtils.getCurrentCountry();
-			boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
-					country);
+			boolean blocked =
+					circumventionProvider.isTorProbablyBlocked(country);
 			Settings s = callback.getSettings();
 			int network = s.getInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_ALWAYS);

@@ -699,31 +693,49 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				if (!online) {
 					LOG.info("Disabling network, device is offline");
 					enableNetwork(false);
-				} else if (blocked) {
-					LOG.info("Disabling network, country is blocked");
-					enableNetwork(false);
 				} else if (network == PREF_TOR_NETWORK_NEVER
 						|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
 					LOG.info("Disabling network due to data setting");
 					enableNetwork(false);
+				} else if (blocked) {
+					if (circumventionProvider.doBridgesWork(country)) {
+						LOG.info("Enabling network, using bridges");
+						enableBridges(true);
+						enableNetwork(true);
+					} else {
+						LOG.info("Disabling network, country is blocked");
+						enableNetwork(false);
+					}
 				} else {
 					LOG.info("Enabling network");
+					enableBridges(false);
 					enableNetwork(true);
 				}
 			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				logException(LOG, WARNING, e);
 			}
 		});
 	}

+	private void scheduleConnectionStatusUpdate() {
+		Future<?> newConnectivityCheck =
+				scheduler.schedule(this::updateConnectionStatus, 1, MINUTES);
+		Future<?> oldConnectivityCheck =
+				connectivityCheck.getAndSet(newConnectivityCheck);
+		if (oldConnectivityCheck != null) oldConnectivityCheck.cancel(false);
+	}
+
 	private class NetworkStateReceiver extends BroadcastReceiver {

 		@Override
 		public void onReceive(Context ctx, Intent i) {
 			if (!running) return;
-			if (CONNECTIVITY_ACTION.equals(i.getAction())) {
-				LOG.info("Detected connectivity change");
-				updateConnectionStatus();
+			String action = i.getAction();
+			if (LOG.isLoggable(INFO)) LOG.info("Received broadcast " + action);
+			updateConnectionStatus();
+			if (ACTION_SCREEN_ON.equals(action)
+					|| ACTION_SCREEN_OFF.equals(action)) {
+				scheduleConnectionStatusUpdate();
 			}
 		}
 	}
@@ -746,7 +758,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {

 		private synchronized void enableNetwork(boolean enable) {
 			networkEnabled = enable;
-			circuitBuilt = false;
+			if (!enable) circuitBuilt = false;
 		}

 		private synchronized boolean isConnected() {
--- a/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPluginFactory.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPluginFactory.java
@@ -12,11 +12,12 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
-import org.briarproject.bramble.api.reporting.DevReporter;
+import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.util.AndroidUtils;

 import java.util.concurrent.Executor;
+import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;

 import javax.annotation.concurrent.Immutable;
@@ -36,24 +37,30 @@ public class TorPluginFactory implements DuplexPluginFactory {
 	private static final double BACKOFF_BASE = 1.2;

 	private final Executor ioExecutor;
+	private final ScheduledExecutorService scheduler;
 	private final Context appContext;
 	private final LocationUtils locationUtils;
-	private final DevReporter reporter;
 	private final EventBus eventBus;
 	private final SocketFactory torSocketFactory;
 	private final BackoffFactory backoffFactory;
+	private final CircumventionProvider circumventionProvider;
+	private final Clock clock;

-	public TorPluginFactory(Executor ioExecutor, Context appContext,
-			LocationUtils locationUtils, DevReporter reporter,
-			EventBus eventBus, SocketFactory torSocketFactory,
-			BackoffFactory backoffFactory) {
+	public TorPluginFactory(Executor ioExecutor,
+			ScheduledExecutorService scheduler, Context appContext,
+			LocationUtils locationUtils, EventBus eventBus,
+			SocketFactory torSocketFactory, BackoffFactory backoffFactory,
+			CircumventionProvider circumventionProvider,
+			Clock clock) {
 		this.ioExecutor = ioExecutor;
+		this.scheduler = scheduler;
 		this.appContext = appContext;
 		this.locationUtils = locationUtils;
-		this.reporter = reporter;
 		this.eventBus = eventBus;
 		this.torSocketFactory = torSocketFactory;
 		this.backoffFactory = backoffFactory;
+		this.circumventionProvider = circumventionProvider;
+		this.clock = clock;
 	}

 	@Override
@@ -89,9 +96,9 @@ public class TorPluginFactory implements DuplexPluginFactory {

 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		TorPlugin plugin = new TorPlugin(ioExecutor, appContext, locationUtils,
-				reporter, torSocketFactory, backoff, callback, architecture,
-				MAX_LATENCY, MAX_IDLE_TIME);
+		TorPlugin plugin = new TorPlugin(ioExecutor, scheduler, appContext,
+				locationUtils, torSocketFactory, clock, backoff, callback,
+				architecture, circumventionProvider, MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}
--- a/bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSecureRandomProvider.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/system/AndroidSecureRandomProvider.java
@@ -9,6 +9,7 @@ import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiManager;
 import android.os.Build;
 import android.os.Parcel;
+import android.os.StrictMode;
 import android.provider.Settings;

 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -66,9 +67,12 @@ class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {

 	@Override
 	protected void writeSeed() {
+		// Silence strict mode
+		StrictMode.ThreadPolicy tp = StrictMode.allowThreadDiskWrites();
 		super.writeSeed();
 		if (Build.VERSION.SDK_INT >= 16 && Build.VERSION.SDK_INT <= 18)
 			applyOpenSslFix();
+		StrictMode.setThreadPolicy(tp);
 	}

 	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
--- a/bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java
@@ -1,7 +1,9 @@
 package org.briarproject.bramble.util;

+import android.annotation.SuppressLint;
 import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
+import android.content.SharedPreferences;
 import android.os.Build;
 import android.provider.Settings;

@@ -10,11 +12,15 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.logging.Logger;

 import static android.content.Context.MODE_PRIVATE;

 public class AndroidUtils {

+	private static final Logger LOG =
+			Logger.getLogger(AndroidUtils.class.getName());
+
 	// Fake Bluetooth address returned by BluetoothAdapter on API 23 and later
 	private static final String FAKE_BLUETOOTH_ADDRESS = "02:00:00:00:00:00";

@@ -35,6 +41,7 @@ public class AndroidUtils {
 	public static String getBluetoothAddress(Context ctx,
 			BluetoothAdapter adapter) {
 		// Return the adapter's address if it's valid and not fake
+		@SuppressLint("HardwareIds")
 		String address = adapter.getAddress();
 		if (isValidBluetoothAddress(address)) return address;
 		// Return the address from settings if it's valid and not fake
@@ -51,17 +58,28 @@ public class AndroidUtils {
 				&& !address.equals(FAKE_BLUETOOTH_ADDRESS);
 	}

-	public static void deleteAppData(Context ctx) {
+	public static void deleteAppData(Context ctx, SharedPreferences... clear) {
+		// Clear and commit shared preferences
+		for (SharedPreferences prefs : clear) {
+			if (!prefs.edit().clear().commit())
+				LOG.warning("Could not clear shared preferences");
+		}
+		// Delete files, except lib and shared_prefs directories
 		File dataDir = new File(ctx.getApplicationInfo().dataDir);
 		File[] children = dataDir.listFiles();
-		if (children != null) {
+		if (children == null) {
+			LOG.warning("Could not list files in app data dir");
+		} else {
 			for (File child : children) {
-				if (!child.getName().equals("lib"))
+				String name = child.getName();
+				if (!name.equals("lib") && !name.equals("shared_prefs")) {
 					IoUtils.deleteFileOrDir(child);
+				}
 			}
 		}
 		// Recreate the cache dir as some OpenGL drivers expect it to exist
-		new File(dataDir, "cache").mkdir();
+		if (!new File(dataDir, "cache").mkdir())
+			LOG.warning("Could not recreate cache dir");
 	}

 	public static File getReportDir(Context ctx) {
--- a/bramble-android/src/main/java/org/briarproject/bramble/util/RenewableWakeLock.java
+++ b/bramble-android/src/main/java/org/briarproject/bramble/util/RenewableWakeLock.java
@@ -0,0 +1,100 @@
+package org.briarproject.bramble.util;
+
+import android.os.PowerManager;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.ThreadSafe;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.INFO;
+
+@ThreadSafe
+@NotNullByDefault
+public class RenewableWakeLock {
+
+	private static final Logger LOG =
+			Logger.getLogger(RenewableWakeLock.class.getName());
+
+	/**
+	 * Automatically release the lock this many milliseconds after it's due
+	 * to have been replaced and released.
+	 */
+	private static final int SAFETY_MARGIN_MS = 10_000;
+
+	private final PowerManager powerManager;
+	private final ScheduledExecutorService scheduler;
+	private final int levelAndFlags;
+	private final String tag;
+	private final long durationMs;
+	private final Runnable renewTask;
+
+	private final Object lock = new Object();
+	@Nullable
+	private PowerManager.WakeLock wakeLock; // Locking: lock
+	@Nullable
+	private ScheduledFuture future; // Locking: lock
+
+	public RenewableWakeLock(PowerManager powerManager,
+			ScheduledExecutorService scheduler, int levelAndFlags, String tag,
+			long duration, TimeUnit timeUnit) {
+		this.powerManager = powerManager;
+		this.scheduler = scheduler;
+		this.levelAndFlags = levelAndFlags;
+		this.tag = tag;
+		durationMs = MILLISECONDS.convert(duration, timeUnit);
+		renewTask = this::renew;
+	}
+
+	public void acquire() {
+		if (LOG.isLoggable(INFO)) LOG.info("Acquiring wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock != null) {
+				LOG.info("Already acquired");
+				return;
+			}
+			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+			wakeLock.setReferenceCounted(false);
+			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
+			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
+		}
+	}
+
+	private void renew() {
+		if (LOG.isLoggable(INFO)) LOG.info("Renewing wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			PowerManager.WakeLock oldWakeLock = wakeLock;
+			wakeLock = powerManager.newWakeLock(levelAndFlags, tag);
+			wakeLock.setReferenceCounted(false);
+			wakeLock.acquire(durationMs + SAFETY_MARGIN_MS);
+			oldWakeLock.release();
+			future = scheduler.schedule(renewTask, durationMs, MILLISECONDS);
+		}
+	}
+
+	public void release() {
+		if (LOG.isLoggable(INFO)) LOG.info("Releasing wake lock " + tag);
+		synchronized (lock) {
+			if (wakeLock == null) {
+				LOG.info("Already released");
+				return;
+			}
+			if (future == null) throw new AssertionError();
+			future.cancel(false);
+			future = null;
+			wakeLock.release();
+			wakeLock = null;
+		}
+	}
+}
+
--- a/bramble-android/src/main/res/raw/bridges
+++ b/bramble-android/src/main/res/raw/bridges
@@ -0,0 +1,5 @@
+Bridge 131.252.210.150:8081 0E858AC201BF0F3FA3C462F64844CBFFC7297A42
+Bridge 67.205.189.122:8443 12D64D5D44E20169585E7378580C0D33A872AD98
+Bridge 45.32.148.146:8443 0CE016FB2462D8BF179AE71F7D702D09DEAC3F1D
+Bridge 148.251.90.59:7510 019F727CA6DCA6CA5C90B55E477B7D87981E75BC
+#Bridge 128.105.214.161:8081 1E326AAFB3FCB515015250D8FCCC8E37F91A153B
--- a/bramble-api/build.gradle
+++ b/bramble-api/build.gradle
@@ -2,6 +2,7 @@ apply plugin: 'java-library'
 sourceCompatibility = 1.8
 targetCompatibility = 1.8

+apply plugin: 'ru.vyarus.animalsniffer'
 apply plugin: 'witness'

 dependencies {
@@ -14,6 +15,8 @@ dependencies {
 	testImplementation "org.jmock:jmock-legacy:2.8.2"
 	testImplementation "org.hamcrest:hamcrest-library:1.3"
 	testImplementation "org.hamcrest:hamcrest-core:1.3"
+
+	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
 }

 dependencyVerification {
@@ -26,6 +29,9 @@ dependencyVerification {
 			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
 			'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
 			'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+			'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
+			'org.codehaus.mojo:animal-sniffer-ant-tasks:1.16:animal-sniffer-ant-tasks-1.16.jar:890040976fbe2d584619a6a61b1fd2e925b3b5eb342a85eb2762c467c0d64e90',
+			'org.codehaus.mojo:animal-sniffer:1.16:animal-sniffer-1.16.jar:72be8bcc226ba43b937c722a08a07852bfa1b11400089265d5df0ee7b38b1d52',
 			'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
 			'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
 			'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
@@ -33,6 +39,7 @@ dependencyVerification {
 			'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
 			'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
 			'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
+			'org.ow2.asm:asm-all:5.2:asm-all-5.2.jar:7fbffbc1db3422e2101689fd88df8384b15817b52b9b2b267b9f6d2511dc198d',
 			'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
 	]
 }
@@ -48,8 +55,3 @@ task jarTest(type: Jar, dependsOn: testClasses) {
 artifacts {
 	testOutput jarTest
 }
-
-// If a Java 6 JRE is available, check we're not using any Java 7 or 8 APIs
-tasks.withType(JavaCompile) {
-	useJava6StandardLibrary(it)
-}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/Multiset.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/Multiset.java
@@ -0,0 +1,101 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
+
+import javax.annotation.concurrent.NotThreadSafe;
+
+@NotThreadSafe
+@NotNullByDefault
+public class Multiset<T> {
+
+	private final Map<T, Integer> map = new HashMap<>();
+
+	private int total = 0;
+
+	/**
+	 * Returns how many items the multiset contains in total.
+	 */
+	public int getTotal() {
+		return total;
+	}
+
+	/**
+	 * Returns how many unique items the multiset contains.
+	 */
+	public int getUnique() {
+		return map.size();
+	}
+
+	/**
+	 * Returns how many of the given item the multiset contains.
+	 */
+	public int getCount(T t) {
+		Integer count = map.get(t);
+		return count == null ? 0 : count;
+	}
+
+	/**
+	 * Adds the given item to the multiset and returns how many of the item
+	 * the multiset now contains.
+	 */
+	public int add(T t) {
+		Integer count = map.get(t);
+		if (count == null) count = 0;
+		map.put(t, count + 1);
+		total++;
+		return count + 1;
+	}
+
+	/**
+	 * Removes the given item from the multiset and returns how many of the
+	 * item the multiset now contains.
+	 * @throws NoSuchElementException if the item is not in the multiset.
+	 */
+	public int remove(T t) {
+		Integer count = map.get(t);
+		if (count == null) throw new NoSuchElementException();
+		if (count == 1) map.remove(t);
+		else map.put(t, count - 1);
+		total--;
+		return count - 1;
+	}
+
+	/**
+	 * Removes all occurrences of the given item from the multiset.
+	 */
+	public int removeAll(T t) {
+		Integer count = map.remove(t);
+		if (count == null) return 0;
+		total -= count;
+		return count;
+	}
+
+	/**
+	 * Returns true if the multiset contains any occurrences of the given item.
+	 */
+	public boolean contains(T t) {
+		return map.containsKey(t);
+	}
+
+	/**
+	 * Removes all items from the multiset.
+	 */
+	public void clear() {
+		map.clear();
+		total = 0;
+	}
+
+	/**
+	 * Returns the set of unique items the multiset contains. The returned set
+	 * is unmodifiable.
+	 */
+	public Set<T> keySet() {
+		return Collections.unmodifiableSet(map.keySet());
+	}
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/UnsupportedVersionException.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/UnsupportedVersionException.java
@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api;
+
+import java.io.IOException;
+
+/**
+ * An exception that indicates an unrecoverable version mismatch.
+ */
+public class UnsupportedVersionException extends IOException {
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/client/ClientHelper.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/client/ClientHelper.java
@@ -5,7 +5,10 @@ import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -87,16 +90,30 @@ public interface ClientHelper {
 	BdfDictionary toDictionary(byte[] b, int off, int len)
 			throws FormatException;

+	BdfDictionary toDictionary(TransportProperties transportProperties);
+
+	BdfDictionary toDictionary(Map<TransportId, TransportProperties> map);
+
 	BdfList toList(byte[] b, int off, int len) throws FormatException;

 	BdfList toList(byte[] b) throws FormatException;

 	BdfList toList(Message m) throws FormatException;

+	BdfList toList(Author a);
+
 	byte[] sign(String label, BdfList toSign, byte[] privateKey)
 			throws FormatException, GeneralSecurityException;

-	void verifySignature(String label, byte[] sig, byte[] publicKey,
-			BdfList signed) throws FormatException, GeneralSecurityException;
+	void verifySignature(byte[] signature, String label, BdfList signed,
+			byte[] publicKey) throws FormatException, GeneralSecurityException;
+
+	Author parseAndValidateAuthor(BdfList author) throws FormatException;
+
+	TransportProperties parseAndValidateTransportProperties(
+			BdfDictionary properties) throws FormatException;
+
+	Map<TransportId, TransportProperties> parseAndValidateTransportPropertiesMap(
+			BdfDictionary properties) throws FormatException;

 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupFactory.java
@@ -12,18 +12,19 @@ public interface ContactGroupFactory {
 	/**
 	 * Creates a group that is not shared with any contacts.
 	 */
-	Group createLocalGroup(ClientId clientId);
+	Group createLocalGroup(ClientId clientId, int majorVersion);

 	/**
 	 * Creates a group for the given client to share with the given contact.
 	 */
-	Group createContactGroup(ClientId clientId, Contact contact);
+	Group createContactGroup(ClientId clientId, int majorVersion,
+			Contact contact);

 	/**
 	 * Creates a group for the given client to share between the given authors
 	 * identified by their AuthorIds.
 	 */
-	Group createContactGroup(ClientId clientId, AuthorId authorId1,
-			AuthorId authorId2);
+	Group createContactGroup(ClientId clientId, int majorVersion,
+			AuthorId authorId1, AuthorId authorId2);

 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeTask.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactExchangeTask.java
@@ -12,6 +12,32 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
@NotNullByDefault
 public interface ContactExchangeTask {

+	/**
+	 * The current version of the contact exchange protocol.
+	 */
+	byte PROTOCOL_VERSION = 1;
+
+	/**
+	 * Label for deriving Alice's header key from the master secret.
+	 */
+	String ALICE_KEY_LABEL =
+			"org.briarproject.bramble.contact/ALICE_HEADER_KEY";
+
+	/**
+	 * Label for deriving Bob's header key from the master secret.
+	 */
+	String BOB_KEY_LABEL = "org.briarproject.bramble.contact/BOB_HEADER_KEY";
+
+	/**
+	 * Label for deriving Alice's key binding nonce from the master secret.
+	 */
+	String ALICE_NONCE_LABEL = "org.briarproject.bramble.contact/ALICE_NONCE";
+
+	/**
+	 * Label for deriving Bob's key binding nonce from the master secret.
+	 */
+	String BOB_NONCE_LABEL = "org.briarproject.bramble.contact/BOB_NONCE";
+
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactId.java
@@ -6,7 +6,7 @@ import javax.annotation.concurrent.Immutable;

 /**
 * Type-safe wrapper for an integer that uniquely identifies a contact within
- * the scope of a single node.
+ * the scope of the local device.
 */
@Immutable
@NotNullByDefault
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactManager.java
@@ -5,6 +5,7 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;

 import java.util.Collection;
@@ -13,30 +14,40 @@ import java.util.Collection;
 public interface ContactManager {

 	/**
-	 * Registers a hook to be called whenever a contact is added.
+	 * Registers a hook to be called whenever a contact is added or removed.
+	 * This method should be called before
+	 * {@link LifecycleManager#startServices(String)}.
 	 */
-	void registerAddContactHook(AddContactHook hook);
+	void registerContactHook(ContactHook hook);

 	/**
-	 * Registers a hook to be called whenever a contact is removed.
-	 */
-	void registerRemoveContactHook(RemoveContactHook hook);
-
-	/**
-	 * Stores a contact within the given transaction associated with the given
-	 * local and remote pseudonyms, and returns an ID for the contact.
+	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * derives and stores transport keys for each transport, and returns an ID
+	 * for the contact.
+	 *
+	 * @param alice true if the local party is Alice
 	 */
 	ContactId addContact(Transaction txn, Author remote, AuthorId local,
 			SecretKey master, long timestamp, boolean alice, boolean verified,
 			boolean active) throws DbException;

 	/**
-	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * Stores a contact associated with the given local and remote pseudonyms
 	 * and returns an ID for the contact.
 	 */
-	ContactId addContact(Author remote, AuthorId local,
-			SecretKey master, long timestamp, boolean alice, boolean verified,
-			boolean active) throws DbException;
+	ContactId addContact(Transaction txn, Author remote, AuthorId local,
+			boolean verified, boolean active) throws DbException;
+
+	/**
+	 * Stores a contact associated with the given local and remote pseudonyms,
+	 * derives and stores transport keys for each transport, and returns an ID
+	 * for the contact.
+	 *
+	 * @param alice true if the local party is Alice
+	 */
+	ContactId addContact(Author remote, AuthorId local, SecretKey master,
+			long timestamp, boolean alice, boolean verified, boolean active)
+			throws DbException;

 	/**
 	 * Returns the contact with the given ID.
@@ -94,11 +105,10 @@ public interface ContactManager {
 	boolean contactExists(AuthorId remoteAuthorId, AuthorId localAuthorId)
 			throws DbException;

-	interface AddContactHook {
-		void addingContact(Transaction txn, Contact c) throws DbException;
-	}
+	interface ContactHook {
+
+		void addingContact(Transaction txn, Contact c) throws DbException;

-	interface RemoveContactHook {
 		void removingContact(Transaction txn, Contact c) throws DbException;
 	}
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/contact/RecordTypes.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/contact/RecordTypes.java
@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.contact;
+
+/**
+ * Record types for the contact exchange protocol.
+ */
+public interface RecordTypes {
+
+	byte CONTACT_INFO = 0;
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoComponent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoComponent.java
@@ -1,11 +1,13 @@
 package org.briarproject.bramble.api.crypto;

-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.TransportKeys;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;

 import java.security.GeneralSecurityException;
 import java.security.SecureRandom;

+import javax.annotation.Nullable;
+
+@NotNullByDefault
 public interface CryptoComponent {

 	SecretKey generateSecretKey();
@@ -23,153 +25,83 @@ public interface CryptoComponent {
 	KeyParser getMessageKeyParser();

 	/**
-	 * Derives a stream header key from the given master secret.
-	 * @param alice whether the key is for use by Alice or Bob.
-	 */
-	SecretKey deriveHeaderKey(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a message authentication code key from the given master secret.
-	 * @param alice whether the key is for use by Alice or Bob.
-	 */
-	SecretKey deriveMacKey(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a nonce from the given master secret for one of the parties to
-	 * sign.
-	 * @param alice whether the nonce is for use by Alice or Bob.
-	 */
-	byte[] deriveSignatureNonce(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a commitment to the provided public key.
-	 * <p/>
-	 * Part of BQP.
+	 * Derives another secret key from the given secret key.
 	 *
-	 * @param publicKey the public key
-	 * @return the commitment to the provided public key.
+	 * @param label a namespaced label indicating the purpose of the derived
+	 * key, to prevent it from being repurposed or colliding with a key derived
+	 * for another purpose
 	 */
-	byte[] deriveKeyCommitment(byte[] publicKey);
+	SecretKey deriveKey(String label, SecretKey k, byte[]... inputs);

 	/**
 	 * Derives a common shared secret from two public keys and one of the
 	 * corresponding private keys.
-	 * <p/>
-	 * Part of BQP.
 	 *
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
+	 * @param label a namespaced label indicating the purpose of this shared
+	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * secret derived for another purpose
+	 * @param theirPublicKey the public key of the remote party
+	 * @param ourKeyPair the key pair of the local party
 	 * @return the shared secret
-	 * @throws GeneralSecurityException
 	 */
-	SecretKey deriveSharedSecret(byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice) throws GeneralSecurityException;
+	SecretKey deriveSharedSecret(String label, PublicKey theirPublicKey,
+			KeyPair ourKeyPair, byte[]... inputs)
+			throws GeneralSecurityException;

 	/**
-	 * Derives the content of a confirmation record.
-	 * <p/>
-	 * Part of BQP.
+	 * Signs the given byte[] with the given private key.
 	 *
-	 * @param sharedSecret the common shared secret
-	 * @param theirPayload the commit payload from the remote party
-	 * @param ourPayload the commit payload we sent
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
-	 * @param aliceRecord true if the confirmation record is for use by Alice
-	 * @return the confirmation record
-	 */
-	byte[] deriveConfirmationRecord(SecretKey sharedSecret,
-			byte[] theirPayload, byte[] ourPayload,
-			byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice, boolean aliceRecord);
-
-	/**
-	 * Derives a master secret from the given shared secret.
-	 * <p/>
-	 * Part of BQP.
-	 *
-	 * @param sharedSecret the common shared secret
-	 * @return the master secret
-	 */
-	SecretKey deriveMasterSecret(SecretKey sharedSecret);
-
-	/**
-	 * Derives a master secret from two public keys and one of the corresponding
-	 * private keys.
-	 * <p/>
-	 * This is a helper method that calls
-	 * deriveMasterSecret(deriveSharedSecret(theirPublicKey, ourKeyPair, alice))
-	 *
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
-	 * @return the shared secret
-	 * @throws GeneralSecurityException
-	 */
-	SecretKey deriveMasterSecret(byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice) throws GeneralSecurityException;
-
-	/**
-	 * Derives initial transport keys for the given transport in the given
-	 * rotation period from the given master secret.
-	 * @param alice whether the keys are for use by Alice or Bob.
-	 */
-	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
-			long rotationPeriod, boolean alice);
-
-	/**
-	 * Rotates the given transport keys to the given rotation period. If the
-	 * keys are for a future rotation period they are not rotated.
-	 */
-	TransportKeys rotateTransportKeys(TransportKeys k, long rotationPeriod);
-
-	/** Encodes the pseudo-random tag that is used to recognise a stream. */
-	void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
-			long streamNumber);
-
-	/**
-	 * Signs the given byte[] with the given PrivateKey.
-	 *
-	 * @param label A label specific to this signature
-	 *              to ensure that the signature cannot be repurposed
+	 * @param label a namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
 	 */
 	byte[] sign(String label, byte[] toSign, byte[] privateKey)
 			throws GeneralSecurityException;

 	/**
-	 * Verifies that the given signature is valid for the signedData
-	 * and the given publicKey.
+	 * Verifies that the given signature is valid for the signed data
+	 * and the given public key.
 	 *
-	 * @param label A label that was specific to this signature
-	 *              to ensure that the signature cannot be repurposed
+	 * @param label a namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
 	 * @return true if the signature was valid, false otherwise.
 	 */
-	boolean verify(String label, byte[] signedData, byte[] publicKey,
-			byte[] signature) throws GeneralSecurityException;
+	boolean verifySignature(byte[] signature, String label, byte[] signed,
+			byte[] publicKey) throws GeneralSecurityException;

 	/**
 	 * Returns the hash of the given inputs. The inputs are unambiguously
 	 * combined by prefixing each input with its length.
 	 *
-	 * @param label A label specific to this hash to ensure that hashes
-	 *              calculated for distinct purposes don't collide.
+	 * @param label a namespaced label indicating the purpose of this hash, to
+	 * prevent it from being repurposed or colliding with a hash created for
+	 * another purpose
 	 */
 	byte[] hash(String label, byte[]... inputs);

-	/**
-	 * Returns the length of hashes produced by
-	 * the {@link CryptoComponent#hash(String, byte[]...)} method.
-	 */
-	int getHashLength();
-
 	/**
 	 * Returns a message authentication code with the given key over the
 	 * given inputs. The inputs are unambiguously combined by prefixing each
 	 * input with its length.
+	 *
+	 * @param label a namespaced label indicating the purpose of this MAC, to
+	 * prevent it from being repurposed or colliding with a MAC created for
+	 * another purpose
 	 */
-	byte[] mac(SecretKey macKey, byte[]... inputs);
+	byte[] mac(String label, SecretKey macKey, byte[]... inputs);
+
+	/**
+	 * Verifies that the given message authentication code is valid for the
+	 * given secret key and inputs.
+	 *
+	 * @param label a namespaced label indicating the purpose of this MAC, to
+	 * prevent it from being repurposed or colliding with a MAC created for
+	 * another purpose
+	 * @return true if the MAC was valid, false otherwise.
+	 */
+	boolean verifyMac(byte[] mac, String label, SecretKey macKey,
+			byte[]... inputs);

 	/**
 	 * Encrypts and authenticates the given plaintext so it can be written to
@@ -185,6 +117,7 @@ public interface CryptoComponent {
 	 * given password. Returns null if the ciphertext cannot be decrypted and
 	 * authenticated (for example, if the password is wrong).
 	 */
+	@Nullable
 	byte[] decryptWithPassword(byte[] ciphertext, String password);

 	/**
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoConstants.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoConstants.java
@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api.crypto;
+
+public interface CryptoConstants {
+
+	/**
+	 * The maximum length of an agreement public key in bytes.
+	 */
+	int MAX_AGREEMENT_PUBLIC_KEY_BYTES = 32;
+
+	/**
+	 * The maximum length of a signature public key in bytes.
+	 */
+	int MAX_SIGNATURE_PUBLIC_KEY_BYTES = 32;
+
+	/**
+	 * The maximum length of a signature in bytes.
+	 */
+	int MAX_SIGNATURE_BYTES = 64;
+
+	/**
+	 * The length of a MAC in bytes.
+	 */
+	int MAC_BYTES = SecretKey.LENGTH;
+
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyAgreementCrypto.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyAgreementCrypto.java
@@ -0,0 +1,50 @@
+package org.briarproject.bramble.api.crypto;
+
+/**
+ * Crypto operations for the key agreement protocol - see
+ * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BQP.md
+ */
+public interface KeyAgreementCrypto {
+
+	/**
+	 * Hash label for public key commitment.
+	 */
+	String COMMIT_LABEL = "org.briarproject.bramble.keyagreement/COMMIT";
+
+	/**
+	 * Key derivation label for confirmation record.
+	 */
+	String CONFIRMATION_KEY_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_KEY";
+
+	/**
+	 * MAC label for confirmation record.
+	 */
+	String CONFIRMATION_MAC_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_MAC";
+
+	/**
+	 * Derives a commitment to the provided public key.
+	 *
+	 * @param publicKey the public key
+	 * @return the commitment to the provided public key.
+	 */
+	byte[] deriveKeyCommitment(PublicKey publicKey);
+
+	/**
+	 * Derives the content of a confirmation record.
+	 *
+	 * @param sharedSecret the common shared secret
+	 * @param theirPayload the key exchange payload of the remote party
+	 * @param ourPayload the key exchange payload of the local party
+	 * @param theirPublicKey the ephemeral public key of the remote party
+	 * @param ourKeyPair our ephemeral key pair of the local party
+	 * @param alice true if the local party is Alice
+	 * @param aliceRecord true if the confirmation record is for use by Alice
+	 * @return the confirmation record
+	 */
+	byte[] deriveConfirmationRecord(SecretKey sharedSecret,
+			byte[] theirPayload, byte[] ourPayload,
+			PublicKey theirPublicKey, KeyPair ourKeyPair,
+			boolean alice, boolean aliceRecord);
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyPair.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/KeyPair.java
@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.concurrent.Immutable;

 /**
- * A key pair consisting of a {@link PublicKey} and a {@link PrivateKey).
+ * A key pair consisting of a {@link PublicKey} and a {@link PrivateKey}.
 */
@Immutable
@NotNullByDefault
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/TransportCrypto.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/crypto/TransportCrypto.java
@@ -0,0 +1,33 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.TransportKeys;
+
+/**
+ * Crypto operations for the transport security protocol - see
+ * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BTP.md
+ */
+public interface TransportCrypto {
+
+	/**
+	 * Derives initial transport keys for the given transport in the given
+	 * rotation period from the given master secret.
+	 *
+	 * @param alice whether the keys are for use by Alice or Bob.
+	 * @param active whether the keys are usable for outgoing streams.
+	 */
+	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
+			long rotationPeriod, boolean alice, boolean active);
+
+	/**
+	 * Rotates the given transport keys to the given rotation period. If the
+	 * keys are for the given period or any later period they are not rotated.
+	 */
+	TransportKeys rotateTransportKeys(TransportKeys k, long rotationPeriod);
+
+	/**
+	 * Encodes the pseudo-random tag that is used to recognise a stream.
+	 */
+	void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
+			long streamNumber);
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java
@@ -24,9 +24,9 @@ public class BdfDictionary extends TreeMap<String, Object> {
 	 * );
 	 * </pre>
 	 */
-	public static BdfDictionary of(Entry<String, Object>... entries) {
+	public static BdfDictionary of(Entry<String, ?>... entries) {
 		BdfDictionary d = new BdfDictionary();
-		for (Entry<String, Object> e : entries) d.put(e.getKey(), e.getValue());
+		for (Entry<String, ?> e : entries) d.put(e.getKey(), e.getValue());
 		return d;
 	}

@@ -34,7 +34,7 @@ public class BdfDictionary extends TreeMap<String, Object> {
 		super();
 	}

-	public BdfDictionary(Map<String, Object> m) {
+	public BdfDictionary(Map<String, ?> m) {
 		super(m);
 	}

--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReader.java
@@ -8,6 +8,7 @@ import java.io.IOException;
 public interface BdfReader {

 	int DEFAULT_NESTED_LIMIT = 5;
+	int DEFAULT_MAX_BUFFER_SIZE = 64 * 1024;

 	boolean eof() throws IOException;

@@ -39,13 +40,13 @@ public interface BdfReader {

 	boolean hasString() throws IOException;

-	String readString(int maxLength) throws IOException;
+	String readString() throws IOException;

 	void skipString() throws IOException;

 	boolean hasRaw() throws IOException;

-	byte[] readRaw(int maxLength) throws IOException;
+	byte[] readRaw() throws IOException;

 	void skipRaw() throws IOException;

--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReaderFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfReaderFactory.java
@@ -9,5 +9,6 @@ public interface BdfReaderFactory {

 	BdfReader createReader(InputStream in);

-	BdfReader createReader(InputStream in, int nestedLimit);
+	BdfReader createReader(InputStream in, int nestedLimit,
+			int maxBufferSize);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/data/ObjectReader.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/data/ObjectReader.java
@@ -1,11 +0,0 @@
-package org.briarproject.bramble.api.data;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.io.IOException;
-
-@NotNullByDefault
-public interface ObjectReader<T> {
-
-	T readObject(BdfReader r) throws IOException;
-}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooNewException.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooNewException.java
@@ -0,0 +1,7 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when the database uses a newer schema than the current code.
+ */
+public class DataTooNewException extends DbException {
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooOldException.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/db/DataTooOldException.java
@@ -0,0 +1,8 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when the database uses an older schema than the current code and
+ * cannot be migrated.
+ */
+public class DataTooOldException extends DbException {
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java
@@ -18,7 +18,8 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
-import org.briarproject.bramble.api.sync.ValidationManager;
+import org.briarproject.bramble.api.transport.KeySet;
+import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.TransportKeys;

 import java.util.Collection;
@@ -37,8 +38,13 @@ public interface DatabaseComponent {

 	/**
 	 * Opens the database and returns true if the database already existed.
+	 *
+	 * @throws DataTooNewException if the data uses a newer schema than the
+	 * current code
+	 * @throws DataTooOldException if the data uses an older schema than the
+	 * current code and cannot be migrated
 	 */
-	boolean open() throws DbException;
+	boolean open(@Nullable MigrationListener listener) throws DbException;

 	/**
 	 * Waits for any open transactions to finish and closes the database.
@@ -98,10 +104,11 @@ public interface DatabaseComponent {
 			throws DbException;

 	/**
-	 * Stores transport keys for a newly added contact.
+	 * Stores the given transport keys for the given contact and returns a
+	 * key set ID.
 	 */
-	void addTransportKeys(Transaction txn, ContactId c, TransportKeys k)
-			throws DbException;
+	KeySetId addTransportKeys(Transaction txn, ContactId c,
+			TransportKeys k) throws DbException;

 	/**
 	 * Returns true if the database contains the given contact for the given
@@ -123,8 +130,8 @@ public interface DatabaseComponent {

 	/**
 	 * Deletes the message with the given ID. Unlike
-	 * {@link #removeMessage(Transaction, MessageId)}, the message ID and any
-	 * other associated data are not deleted.
+	 * {@link #removeMessage(Transaction, MessageId)}, the message ID,
+	 * dependencies, metadata, and any other associated state are not deleted.
 	 */
 	void deleteMessage(Transaction txn, MessageId m) throws DbException;

@@ -228,7 +235,8 @@ public interface DatabaseComponent {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<Group> getGroups(Transaction txn, ClientId c) throws DbException;
+	Collection<Group> getGroups(Transaction txn, ClientId c, int majorVersion)
+			throws DbException;

 	/**
 	 * Returns the given group's visibility to the given contact, or
@@ -254,31 +262,38 @@ public interface DatabaseComponent {
 	Collection<LocalAuthor> getLocalAuthors(Transaction txn) throws DbException;

 	/**
-	 * Returns the IDs of any messages that need to be validated by the given
-	 * client.
+	 * Returns the IDs of all delivered messages in the given group.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToValidate(Transaction txn, ClientId c)
+	Collection<MessageId> getMessageIds(Transaction txn, GroupId g)
+		throws DbException;
+
+	/**
+	 * Returns the IDs of any messages that need to be validated.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<MessageId> getMessagesToValidate(Transaction txn)
 			throws DbException;

 	/**
-	 * Returns the IDs of any messages that are valid but pending delivery due
-	 * to dependencies on other messages for the given client.
+	 * Returns the IDs of any messages that are pending delivery due to
+	 * dependencies on other messages.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getPendingMessages(Transaction txn, ClientId c)
+	Collection<MessageId> getPendingMessages(Transaction txn)
 			throws DbException;

 	/**
-	 * Returns the IDs of any messages from the given client
-	 * that have a shared dependent, but are still not shared themselves.
+	 * Returns the IDs of any messages that have shared dependents but have
+	 * not yet been shared themselves.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToShare(Transaction txn,
-			ClientId c) throws DbException;
+	Collection<MessageId> getMessagesToShare(Transaction txn)
+			throws DbException;

 	/**
 	 * Returns the message with the given ID, in serialised form, or null if
@@ -298,9 +313,9 @@ public interface DatabaseComponent {
 			throws DbException;

 	/**
-	 * Returns the metadata for any messages in the given group with metadata
-	 * that matches all entries in the given query. If the query is empty, the
-	 * metadata for all messages is returned.
+	 * Returns the metadata for any delivered messages in the given group with
+	 * metadata that matches all entries in the given query. If the query is
+	 * empty, the metadata for all delivered messages is returned.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -316,8 +331,8 @@ public interface DatabaseComponent {
 			throws DbException;

 	/**
-	 * Returns the metadata for the given delivered and pending message.
-	 * This is meant to be only used by the ValidationManager
+	 * Returns the metadata for the given delivered or pending message.
+	 * This is only meant to be used by the ValidationManager.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -325,8 +340,8 @@ public interface DatabaseComponent {
 			throws DbException;

 	/**
-	 * Returns the status of all messages in the given group with respect to
-	 * the given contact.
+	 * Returns the status of all delivered messages in the given group with
+	 * respect to the given contact.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -335,12 +350,8 @@ public interface DatabaseComponent {

 	/**
 	 * Returns the IDs and states of all dependencies of the given message.
-	 * Missing dependencies have the state
-	 * {@link ValidationManager.State UNKNOWN}.
-	 * Dependencies in other groups have the state
-	 * {@link ValidationManager.State INVALID}.
-	 * Note that these states are not set on the dependencies themselves; the
-	 * returned states should only be taken in the context of the given message.
+	 * For missing dependencies and dependencies in other groups, the state
+	 * {@link State UNKNOWN} is returned.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -348,9 +359,9 @@ public interface DatabaseComponent {
 			throws DbException;

 	/**
-	 * Returns all IDs of messages that depend on the given message.
-	 * Messages in other groups that declare a dependency on the given message
-	 * will be returned even though such dependencies are invalid.
+	 * Returns the IDs and states of all dependents of the given message.
+	 * Dependents in other groups are not returned. If the given message is
+	 * missing, no dependents are returned.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -365,14 +376,24 @@ public interface DatabaseComponent {
 	State getMessageState(Transaction txn, MessageId m) throws DbException;

 	/**
-	 * Returns the status of the given message with respect to the given
-	 * contact.
+	 * Returns the status of the given delivered message with respect to the
+	 * given contact.
 	 * <p/>
 	 * Read-only.
 	 */
 	MessageStatus getMessageStatus(Transaction txn, ContactId c, MessageId m)
 			throws DbException;

+	/*
+	 * Returns the next time (in milliseconds since the Unix epoch) when a
+	 * message is due to be sent to the given contact. The returned value may
+	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE if
+	 * no messages are scheduled to be sent.
+	 * <p/>
+	 * Read-only.
+	 */
+	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
+
 	/**
 	 * Returns all settings in the given namespace.
 	 * <p/>
@@ -385,15 +406,14 @@ public interface DatabaseComponent {
 	 * <p/>
 	 * Read-only.
 	 */
-	Map<ContactId, TransportKeys> getTransportKeys(Transaction txn,
-			TransportId t) throws DbException;
+	Collection<KeySet> getTransportKeys(Transaction txn, TransportId t)
+			throws DbException;

 	/**
-	 * Increments the outgoing stream counter for the given contact and
-	 * transport in the given rotation period .
+	 * Increments the outgoing stream counter for the given transport keys.
 	 */
-	void incrementStreamCounter(Transaction txn, ContactId c, TransportId t,
-			long rotationPeriod) throws DbException;
+	void incrementStreamCounter(Transaction txn, TransportId t, KeySetId k)
+			throws DbException;

 	/**
 	 * Merges the given metadata with the existing metadata for the given
@@ -463,6 +483,12 @@ public interface DatabaseComponent {
 	 */
 	void removeTransport(Transaction txn, TransportId t) throws DbException;

+	/**
+	 * Removes the given transport keys from the database.
+	 */
+	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
+		throws DbException;
+
 	/**
 	 * Marks the given contact as verified.
 	 */
@@ -498,15 +524,21 @@ public interface DatabaseComponent {
 			Collection<MessageId> dependencies) throws DbException;

 	/**
-	 * Sets the reordering window for the given contact and transport in the
+	 * Sets the reordering window for the given key set and transport in the
 	 * given rotation period.
 	 */
-	void setReorderingWindow(Transaction txn, ContactId c, TransportId t,
+	void setReorderingWindow(Transaction txn, KeySetId k, TransportId t,
 			long rotationPeriod, long base, byte[] bitmap) throws DbException;

+	/**
+	 * Marks the given transport keys as usable for outgoing streams.
+	 */
+	void setTransportKeysActive(Transaction txn, TransportId t, KeySetId k)
+		throws DbException;
+
 	/**
 	 * Stores the given transport keys, deleting any keys they have replaced.
 	 */
-	void updateTransportKeys(Transaction txn,
-			Map<ContactId, TransportKeys> keys) throws DbException;
+	void updateTransportKeys(Transaction txn, Collection<KeySet> keys)
+			throws DbException;
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseConfig.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseConfig.java
@@ -14,6 +14,8 @@ public interface DatabaseConfig {

 	File getDatabaseDirectory();

+	File getDatabaseKeyDirectory();
+
 	void setEncryptionKey(SecretKey key);

 	@Nullable
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/db/MigrationListener.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/db/MigrationListener.java
@@ -0,0 +1,11 @@
+package org.briarproject.bramble.api.db;
+
+public interface MigrationListener {
+
+	/**
+	 * This is called when a migration is started while opening the database.
+	 * It will be called once for each migration being applied.
+	 */
+	void onMigrationRun();
+
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/identity/Author.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/identity/Author.java
@@ -1,11 +1,13 @@
 package org.briarproject.bramble.api.identity;

 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.io.UnsupportedEncodingException;
+import org.briarproject.bramble.util.StringUtils;

 import javax.annotation.concurrent.Immutable;

+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
+
 /**
 * A pseudonym for a user.
 */
@@ -17,20 +19,25 @@ public class Author {
 		NONE, ANONYMOUS, UNKNOWN, UNVERIFIED, VERIFIED, OURSELVES
 	}

+	/**
+	 * The current version of the author structure.
+	 */
+	public static final int FORMAT_VERSION = 1;
+
 	private final AuthorId id;
+	private final int formatVersion;
 	private final String name;
 	private final byte[] publicKey;

-	public Author(AuthorId id, String name, byte[] publicKey) {
-		int length;
-		try {
-			length = name.getBytes("UTF-8").length;
-		} catch (UnsupportedEncodingException e) {
-			throw new RuntimeException(e);
-		}
-		if (length == 0 || length > AuthorConstants.MAX_AUTHOR_NAME_LENGTH)
+	public Author(AuthorId id, int formatVersion, String name,
+			byte[] publicKey) {
+		int nameLength = StringUtils.toUtf8(name).length;
+		if (nameLength == 0 || nameLength > MAX_AUTHOR_NAME_LENGTH)
+			throw new IllegalArgumentException();
+		if (publicKey.length == 0 || publicKey.length > MAX_PUBLIC_KEY_LENGTH)
 			throw new IllegalArgumentException();
 		this.id = id;
+		this.formatVersion = formatVersion;
 		this.name = name;
 		this.publicKey = publicKey;
 	}
@@ -42,6 +49,13 @@ public class Author {
 		return id;
 	}

+	/**
+	 * Returns the version of the author structure used to create the author.
+	 */
+	public int getFormatVersion() {
+		return formatVersion;
+	}
+
 	/**
 	 * Returns the author's name.
 	 */
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorConstants.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorConstants.java
@@ -1,5 +1,8 @@
 package org.briarproject.bramble.api.identity;

+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_SIGNATURE_BYTES;
+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_SIGNATURE_PUBLIC_KEY_BYTES;
+
 public interface AuthorConstants {

 	/**
@@ -8,26 +11,14 @@ public interface AuthorConstants {
 	int MAX_AUTHOR_NAME_LENGTH = 50;

 	/**
-	 * The maximum length of a public key in bytes.
-	 * <p>
-	 * Public keys use SEC1 format: 0x04 x y, where x and y are unsigned
-	 * big-endian integers.
-	 * <p>
-	 * For a 256-bit elliptic curve, the maximum length is 2 * 256 / 8 + 1.
+	 * The maximum length of a public key in bytes. This applies to the
+	 * signature algorithm used by the current {@link Author format version}.
 	 */
-	int MAX_PUBLIC_KEY_LENGTH = 65;
+	int MAX_PUBLIC_KEY_LENGTH = MAX_SIGNATURE_PUBLIC_KEY_BYTES;

 	/**
-	 * The maximum length of a signature in bytes.
-	 * <p>
-	 * A signature is an ASN.1 DER sequence containing two integers, r and s.
-	 * The format is 0x30 len1 0x02 len2 r 0x02 len3 s, where len1 is
-	 * len(0x02 len2 r 0x02 len3 s) as a DER length, len2 is len(r) as a DER
-	 * length, len3 is len(s) as a DER length, and r and s are signed
-	 * big-endian integers of minimal length.
-	 * <p>
-	 * For a 256-bit elliptic curve, the lengths are one byte each, so the
-	 * maximum length is 2 * 256 / 8 + 8.
+	 * The maximum length of a signature in bytes. This applies to the
+	 * signature algorithm used by the current {@link Author format version}.
 	 */
-	int MAX_SIGNATURE_LENGTH = 72;
+	int MAX_SIGNATURE_LENGTH = MAX_SIGNATURE_BYTES;
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorFactory.java
@@ -5,8 +5,27 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@NotNullByDefault
 public interface AuthorFactory {

+	/**
+	 * Creates an author with the current format version and the given name and
+	 * public key.
+	 */
 	Author createAuthor(String name, byte[] publicKey);

+	/**
+	 * Creates an author with the given format version, name and public key.
+	 */
+	Author createAuthor(int formatVersion, String name, byte[] publicKey);
+
+	/**
+	 * Creates a local author with the current format version and the given
+	 * name and keys.
+	 */
 	LocalAuthor createLocalAuthor(String name, byte[] publicKey,
 			byte[] privateKey);
+
+	/**
+	 * Creates a local author with the given format version, name and keys.
+	 */
+	LocalAuthor createLocalAuthor(int formatVersion, String name,
+			byte[] publicKey, byte[] privateKey);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorId.java
@@ -16,7 +16,7 @@ public class AuthorId extends UniqueId {
 	/**
 	 * Label for hashing authors to calculate their identities.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.AUTHOR_ID";
+	public static final String LABEL = "org.briarproject.bramble/AUTHOR_ID";

 	public AuthorId(byte[] id) {
 		super(id);
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/identity/LocalAuthor.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/identity/LocalAuthor.java
@@ -14,9 +14,9 @@ public class LocalAuthor extends Author {
 	private final byte[] privateKey;
 	private final long created;

-	public LocalAuthor(AuthorId id, String name, byte[] publicKey,
-			byte[] privateKey, long created) {
-		super(id, name, publicKey);
+	public LocalAuthor(AuthorId id, int formatVersion, String name,
+			byte[] publicKey, byte[] privateKey, long created) {
+		super(id, formatVersion, name, publicKey);
 		this.privateKey = privateKey;
 		this.created = created;
 	}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementConstants.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementConstants.java
@@ -3,9 +3,9 @@ package org.briarproject.bramble.api.keyagreement;
 public interface KeyAgreementConstants {

 	/**
-	 * The current version of the BQP protocol.
+	 * The current version of the BQP protocol. Version number 89 is reserved.
 	 */
-	byte PROTOCOL_VERSION = 2;
+	byte PROTOCOL_VERSION = 4;

 	/**
 	 * The length of the record header in bytes.
@@ -22,7 +22,10 @@ public interface KeyAgreementConstants {
 	 */
 	int COMMIT_LENGTH = 16;

-	long CONNECTION_TIMEOUT = 20 * 1000; // Milliseconds
+	/**
+	 * The connection timeout in milliseconds.
+	 */
+	long CONNECTION_TIMEOUT = 20 * 1000;

 	/**
 	 * The transport identifier for Bluetooth.
@@ -33,4 +36,16 @@ public interface KeyAgreementConstants {
 	 * The transport identifier for LAN.
 	 */
 	int TRANSPORT_ID_LAN = 1;
+
+	/**
+	 * Label for deriving the shared secret.
+	 */
+	String SHARED_SECRET_LABEL =
+			"org.briarproject.bramble.keyagreement/SHARED_SECRET";
+
+	/**
+	 * Label for deriving the master secret.
+	 */
+	String MASTER_SECRET_LABEL =
+			"org.briarproject.bramble.keyagreement/MASTER_SECRET";
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementListener.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementListener.java
@@ -2,7 +2,7 @@ package org.briarproject.bramble.api.keyagreement;

 import org.briarproject.bramble.api.data.BdfList;

-import java.util.concurrent.Callable;
+import java.io.IOException;

 /**
 * An class for managing a particular key agreement listener.
@@ -24,11 +24,11 @@ public abstract class KeyAgreementListener {
 	}

 	/**
-	 * Starts listening for incoming connections, and returns a Callable that
-	 * will return a KeyAgreementConnection when an incoming connection is
-	 * received.
+	 * Blocks until an incoming connection is received and returns it.
+	 *
+	 * @throws IOException if an error occurs or {@link #close()} is called.
 	 */
-	public abstract Callable<KeyAgreementConnection> listen();
+	public abstract KeyAgreementConnection accept() throws IOException;

 	/**
 	 * Closes the underlying server socket.
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementTaskFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementTaskFactory.java
@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.keyagreement;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * Manages tasks for conducting key agreements with remote peers.
- */
-@NotNullByDefault
-public interface KeyAgreementTaskFactory {
-
-	/**
-	 * Gets the current key agreement task.
-	 */
-	KeyAgreementTask createTask();
-}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/event/KeyAgreementStoppedListeningEvent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/event/KeyAgreementStoppedListeningEvent.java
@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api.keyagreement.event;
+
+import org.briarproject.bramble.api.event.Event;
+
+/**
+ * An event that is broadcast when a BQP task stops listening.
+ */
+public class KeyAgreementStoppedListeningEvent extends Event {
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/IoExecutor.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/IoExecutor.java
@@ -12,7 +12,7 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;

 /**
 * Annotation for injecting the executor for long-running IO tasks. Also used
- * for annotating methods that should run on the UI executor.
+ * for annotating methods that should run on the IO executor.
 * <p>
 * The contract of this executor is that tasks may be run concurrently, and
 * submitting a task will never block. Tasks may run indefinitely. Tasks
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java
@@ -21,21 +21,42 @@ public interface LifecycleManager {
 	 * The result of calling {@link #startServices(String)}.
 	 */
 	enum StartResult {
-		ALREADY_RUNNING, DB_ERROR, SERVICE_ERROR, SUCCESS
+		ALREADY_RUNNING,
+		DB_ERROR,
+		DATA_TOO_OLD_ERROR,
+		DATA_TOO_NEW_ERROR,
+		SERVICE_ERROR,
+		SUCCESS
 	}

 	/**
-	 * Registers a {@link Service} to be started and stopped.
+	 * The state the lifecycle can be in.
+	 * Returned by {@link #getLifecycleState()}
+	 */
+	enum LifecycleState {
+
+		STARTING, MIGRATING_DATABASE, STARTING_SERVICES, RUNNING, STOPPING;
+
+		public boolean isAfter(LifecycleState state) {
+			return ordinal() > state.ordinal();
+		}
+	}
+
+	/**
+	 * Registers a {@link Service} to be started and stopped. This method
+	 * should be called before {@link #startServices(String)}.
 	 */
 	void registerService(Service s);

 	/**
-	 * Registers a {@link Client} to be started.
+	 * Registers a {@link Client} to be started. This method should be called
+	 * before {@link #startServices(String)}.
 	 */
 	void registerClient(Client c);

 	/**
-	 * Registers an {@link ExecutorService} to be shut down.
+	 * Registers an {@link ExecutorService} to be shut down. This method
+	 * should be called before {@link #startServices(String)}.
 	 */
 	void registerForShutdown(ExecutorService e);

@@ -71,4 +92,10 @@ public interface LifecycleManager {
 	 * the {@link DatabaseComponent} to be closed before returning.
 	 */
 	void waitForShutdown() throws InterruptedException;
+
+	/**
+	 * Returns the current state of the lifecycle.
+	 */
+	LifecycleState getLifecycleState();
+
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/LifecycleEvent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/LifecycleEvent.java
@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.lifecycle.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState;
+
+/**
+ * An event that is broadcast when the app enters a new lifecycle state.
+ */
+public class LifecycleEvent extends Event {
+
+	private final LifecycleState state;
+
+	public LifecycleEvent(LifecycleState state) {
+		this.state = state;
+	}
+
+	public LifecycleState getLifecycleState() {
+		return state;
+	}
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/ShutdownEvent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/event/ShutdownEvent.java
@@ -1,9 +0,0 @@
-package org.briarproject.bramble.api.lifecycle.event;
-
-import org.briarproject.bramble.api.event.Event;
-
-/**
- * An event that is broadcast when the app is shutting down.
- */
-public class ShutdownEvent extends Event {
-}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/FileConstants.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/FileConstants.java
@@ -0,0 +1,6 @@
+package org.briarproject.bramble.api.plugin;
+
+public interface FileConstants {
+
+	String PROP_PATH = "path";
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/Plugin.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/Plugin.java
@@ -2,8 +2,9 @@ package org.briarproject.bramble.api.plugin;

 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.properties.TransportProperties;

-import java.util.Collection;
+import java.util.Map;

@NotNullByDefault
 public interface Plugin {
@@ -39,21 +40,19 @@ public interface Plugin {
 	boolean isRunning();

 	/**
-	 * Returns true if the plugin's {@link #poll(Collection)} method should be
-	 * called periodically to attempt to establish connections.
+	 * Returns true if the plugin should be polled periodically to attempt to
+	 * establish connections.
 	 */
 	boolean shouldPoll();

 	/**
-	 * Returns the desired interval in milliseconds between calls to the
-	 * plugin's {@link #poll(Collection)} method.
+	 * Returns the desired interval in milliseconds between polling attempts.
 	 */
 	int getPollingInterval();

 	/**
-	 * Attempts to establish connections to contacts, passing any created
-	 * connections to the callback. To avoid creating redundant connections,
-	 * the plugin may exclude the given contacts from polling.
+	 * Attempts to establish connections to the given contacts, passing any
+	 * created connections to the callback.
 	 */
-	void poll(Collection<ContactId> connected);
+	void poll(Map<ContactId, TransportProperties> contacts);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java
@@ -1,12 +1,9 @@
 package org.briarproject.bramble.api.plugin;

-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;

-import java.util.Map;
-
 /**
 * An interface through which a transport plugin interacts with the rest of
 * the application.
@@ -25,17 +22,7 @@ public interface PluginCallback {
 	TransportProperties getLocalProperties();

 	/**
-	 * Returns the plugin's remote transport properties.
-	 */
-	Map<ContactId, TransportProperties> getRemoteProperties();
-
-	/**
-	 * Returns the plugin's remote transport properties for the given contact.
-	 */
-	TransportProperties getRemoteProperties(ContactId c);
-
-	/**
-	 * Merges the given settings with the namespaced settings
+	 * Merges the given settings with the plugin's settings
 	 */
 	void mergeSettings(Settings s);

@@ -45,34 +32,12 @@ public interface PluginCallback {
 	void mergeLocalProperties(TransportProperties p);

 	/**
-	 * Presents the user with a choice among two or more named options and
-	 * returns the user's response. The message may consist of a translatable
-	 * format string and arguments.
-	 *
-	 * @return an index into the array of options indicating the user's choice,
-	 * or -1 if the user cancelled the choice.
-	 */
-	int showChoice(String[] options, String... message);
-
-	/**
-	 * Asks the user to confirm an action and returns the user's response. The
-	 * message may consist of a translatable format string and arguments.
-	 */
-	boolean showConfirmationMessage(String... message);
-
-	/**
-	 * Shows a message to the user. The message may consist of a translatable
-	 * format string and arguments.
-	 */
-	void showMessage(String... message);
-
-	/**
-	 * Signal that the transport got enabled.
+	 * Signals that the transport is enabled.
 	 */
 	void transportEnabled();

 	/**
-	 * Signal that the transport got disabled.
+	 * Signals that the transport is disabled.
 	 */
 	void transportDisabled();
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginConfig.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginConfig.java
@@ -12,4 +12,6 @@ public interface PluginConfig {
 	Collection<DuplexPluginFactory> getDuplexFactories();

 	Collection<SimplexPluginFactory> getSimplexFactories();
+
+	boolean shouldPoll();
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TransportConnectionWriter.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TransportConnectionWriter.java
@@ -22,11 +22,6 @@ public interface TransportConnectionWriter {
 	 */
 	int getMaxIdleTime();

-	/**
-	 * Returns the capacity of the transport connection in bytes.
-	 */
-	long getCapacity();
-
 	/**
 	 * Returns an output stream for writing to the transport connection.
 	 */
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TransportId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TransportId.java
@@ -1,22 +1,23 @@
 package org.briarproject.bramble.api.plugin;

-import java.nio.charset.Charset;
+import org.briarproject.bramble.util.StringUtils;

 /**
- * Type-safe wrapper for a string that uniquely identifies a transport plugin.
+ * Type-safe wrapper for a namespaced string that uniquely identifies a
+ * transport plugin.
 */
 public class TransportId {

 	/**
-	 * The maximum length of transport identifier in UTF-8 bytes.
+	 * The maximum length of a transport identifier in UTF-8 bytes.
 	 */
-	public static int MAX_TRANSPORT_ID_LENGTH = 64;
+	public static int MAX_TRANSPORT_ID_LENGTH = 100;

 	private final String id;

 	public TransportId(String id) {
-		byte[] b = id.getBytes(Charset.forName("UTF-8"));
-		if (b.length == 0 || b.length > MAX_TRANSPORT_ID_LENGTH)
+		int length = StringUtils.toUtf8(id).length;
+		if (length == 0 || length > MAX_TRANSPORT_ID_LENGTH)
 			throw new IllegalArgumentException();
 		this.id = id;
 	}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/AbstractDuplexTransportConnection.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/AbstractDuplexTransportConnection.java
@@ -71,11 +71,6 @@ public abstract class AbstractDuplexTransportConnection
 			return plugin.getMaxIdleTime();
 		}

-		@Override
-		public long getCapacity() {
-			return Long.MAX_VALUE;
-		}
-
 		@Override
 		public OutputStream getOutputStream() throws IOException {
 			return AbstractDuplexTransportConnection.this.getOutputStream();
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPlugin.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPlugin.java
@@ -1,10 +1,10 @@
 package org.briarproject.bramble.api.plugin.duplex;

-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
+import org.briarproject.bramble.api.properties.TransportProperties;

 import javax.annotation.Nullable;

@@ -15,12 +15,11 @@ import javax.annotation.Nullable;
 public interface DuplexPlugin extends Plugin {

 	/**
-	 * Attempts to create and return a connection to the given contact using
-	 * the current transport and configuration properties. Returns null if a
-	 * connection cannot be created.
+	 * Attempts to create and return a connection using the given transport
+	 * properties. Returns null if a connection cannot be created.
 	 */
 	@Nullable
-	DuplexTransportConnection createConnection(ContactId c);
+	DuplexTransportConnection createConnection(TransportProperties p);

 	/**
 	 * Returns true if the plugin supports short-range key agreement.
@@ -36,9 +35,9 @@ public interface DuplexPlugin extends Plugin {

 	/**
 	 * Attempts to connect to the remote peer specified in the given descriptor.
-	 * Returns null if no connection can be established within the given time.
+	 * Returns null if no connection can be established.
 	 */
 	@Nullable
 	DuplexTransportConnection createKeyAgreementConnection(
-			byte[] remoteCommitment, BdfList descriptor, long timeout);
+			byte[] remoteCommitment, BdfList descriptor);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPluginCallback.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPluginCallback.java
@@ -5,7 +5,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginCallback;

 /**
- * An interface for handling connections created by a duplex transport plugin.
+ * An interface through which a duplex plugin interacts with the rest of the
+ * application.
 */
@NotNullByDefault
 public interface DuplexPluginCallback extends PluginCallback {
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/BluetoothEnabledEvent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/BluetoothEnabledEvent.java
@@ -0,0 +1,15 @@
+package org.briarproject.bramble.api.plugin.event;
+
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that informs the Bluetooth plugin that we have enabled the
+ * Bluetooth adapter.
+ */
+@Immutable
+@NotNullByDefault
+public class BluetoothEnabledEvent extends Event {
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/EnableBluetoothEvent.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/EnableBluetoothEvent.java
@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.concurrent.Immutable;

 /**
- * An event asks the Bluetooth plugin to enable the Bluetooth adapter.
+ * An event that asks the Bluetooth plugin to enable the Bluetooth adapter.
 */
@Immutable
@NotNullByDefault
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/simplex/SimplexPlugin.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/simplex/SimplexPlugin.java
@@ -1,10 +1,10 @@
 package org.briarproject.bramble.api.plugin.simplex;

-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+import org.briarproject.bramble.api.properties.TransportProperties;

 import javax.annotation.Nullable;

@@ -15,18 +15,16 @@ import javax.annotation.Nullable;
 public interface SimplexPlugin extends Plugin {

 	/**
-	 * Attempts to create and return a reader for the given contact using the
-	 * current transport and configuration properties. Returns null if a reader
-	 * cannot be created.
+	 * Attempts to create and return a reader for the given transport
+	 * properties. Returns null if a reader cannot be created.
 	 */
 	@Nullable
-	TransportConnectionReader createReader(ContactId c);
+	TransportConnectionReader createReader(TransportProperties p);

 	/**
-	 * Attempts to create and return a writer for the given contact using the
-	 * current transport and configuration properties. Returns null if a writer
-	 * cannot be created.
+	 * Attempts to create and return a writer for the given transport
+	 * properties. Returns null if a writer cannot be created.
 	 */
 	@Nullable
-	TransportConnectionWriter createWriter(ContactId c);
+	TransportConnectionWriter createWriter(TransportProperties p);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/simplex/SimplexPluginCallback.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/plugin/simplex/SimplexPluginCallback.java
@@ -7,8 +7,8 @@ import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;

 /**
- * An interface for handling readers and writers created by a simplex transport
- * plugin.
+ * An interface through which a simplex plugin interacts with the rest of the
+ * application.
 */
@NotNullByDefault
 public interface SimplexPluginCallback extends PluginCallback {
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java
@@ -15,7 +15,17 @@ public interface TransportPropertyManager {
 	/**
 	 * The unique ID of the transport property client.
 	 */
-	ClientId CLIENT_ID = new ClientId("org.briarproject.briar.properties");
+	ClientId CLIENT_ID = new ClientId("org.briarproject.bramble.properties");
+
+	/**
+	 * The current major version of the transport property client.
+	 */
+	int MAJOR_VERSION = 0;
+
+	/**
+	 * The current minor version of the transport property client.
+	 */
+	int MINOR_VERSION = 0;

 	/**
 	 * Stores the given properties received while adding a contact - they will
@@ -32,8 +42,8 @@ public interface TransportPropertyManager {

 	/**
 	 * Returns the local transport properties for all transports.
-	 * <br/>
-	 * TODO: Transaction can be read-only when code is simplified
+	 * <p/>
+	 * Read-only.
 	 */
 	Map<TransportId, TransportProperties> getLocalProperties(Transaction txn)
 			throws DbException;
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/record/Record.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/record/Record.java
@@ -0,0 +1,36 @@
+package org.briarproject.bramble.api.record;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class Record {
+
+	public static final int RECORD_HEADER_BYTES = 4;
+	public static final int MAX_RECORD_PAYLOAD_BYTES = 48 * 1024; // 48 KiB
+
+	private final byte protocolVersion, recordType;
+	private final byte[] payload;
+
+	public Record(byte protocolVersion, byte recordType, byte[] payload) {
+		if (payload.length > MAX_RECORD_PAYLOAD_BYTES)
+			throw new IllegalArgumentException();
+		this.protocolVersion = protocolVersion;
+		this.recordType = recordType;
+		this.payload = payload;
+	}
+
+	public byte getProtocolVersion() {
+		return protocolVersion;
+	}
+
+	public byte getRecordType() {
+		return recordType;
+	}
+
+	public byte[] getPayload() {
+		return payload;
+	}
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordReader.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordReader.java
@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.record;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.EOFException;
+import java.io.IOException;
+
+@NotNullByDefault
+public interface RecordReader {
+
+	/**
+	 * Reads and returns the next record.
+	 *
+	 * @throws EOFException if the end of the stream is reached without reading
+	 * a complete record
+	 */
+	Record readRecord() throws IOException;
+
+	void close() throws IOException;
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordReaderFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordReaderFactory.java
@@ -0,0 +1,8 @@
+package org.briarproject.bramble.api.record;
+
+import java.io.InputStream;
+
+public interface RecordReaderFactory {
+
+	RecordReader createRecordReader(InputStream in);
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriter.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriter.java
@@ -0,0 +1,15 @@
+package org.briarproject.bramble.api.record;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.IOException;
+
+@NotNullByDefault
+public interface RecordWriter {
+
+	void writeRecord(Record r) throws IOException;
+
+	void flush() throws IOException;
+
+	void close() throws IOException;
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriterFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriterFactory.java
@@ -0,0 +1,8 @@
+package org.briarproject.bramble.api.record;
+
+import java.io.OutputStream;
+
+public interface RecordWriterFactory {
+
+	RecordWriter createRecordWriter(OutputStream out);
+}
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevConfig.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevConfig.java
@@ -3,10 +3,14 @@ package org.briarproject.bramble.api.reporting;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;

+import java.io.File;
+
@NotNullByDefault
 public interface DevConfig {

 	PublicKey getDevPublicKey();

 	String getDevOnionAddress();
+
+	File getReportDir();
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevReporter.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevReporter.java
@@ -23,8 +23,6 @@ public interface DevReporter {

 	/**
 	 * Sends any reports previously stored on disk.
-	 *
-	 * @param reportDir the directory where reports are stored.
 	 */
-	void sendReports(File reportDir);
+	void sendReports();
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/ClientId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/ClientId.java
@@ -1,19 +1,29 @@
 package org.briarproject.bramble.api.sync;

 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.util.StringUtils;

 import javax.annotation.concurrent.Immutable;

 /**
- * Wrapper for a name-spaced string that uniquely identifies a sync client.
+ * Type-safe wrapper for a namespaced string that uniquely identifies a sync
+ * client.
 */
@Immutable
@NotNullByDefault
 public class ClientId implements Comparable<ClientId> {

+	/**
+	 * The maximum length of a client identifier in UTF-8 bytes.
+	 */
+	public static int MAX_CLIENT_ID_LENGTH = 100;
+
 	private final String id;

 	public ClientId(String id) {
+		int length = StringUtils.toUtf8(id).length;
+		if (length == 0 || length > MAX_CLIENT_ID_LENGTH)
+			throw new IllegalArgumentException();
 		this.id = id;
 	}

@@ -36,4 +46,8 @@ public class ClientId implements Comparable<ClientId> {
 		return id.hashCode();
 	}

+	@Override
+	public String toString() {
+		return id;
+	}
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/Group.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/Group.java
@@ -5,20 +5,43 @@ import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPT
 public class Group {

 	public enum Visibility {
-		INVISIBLE, // The group is not visible
-		VISIBLE, // The group is visible but messages are not shared
-		SHARED // The group is visible and messages are shared
+
+		INVISIBLE(0), // The group is not visible
+		VISIBLE(1), // The group is visible, messages are accepted but not sent
+		SHARED(2); // The group is visible, messages are accepted and sent
+
+		private final int value;
+
+		Visibility(int value) {
+			this.value = value;
+		}
+
+		public int getValue() {
+			return value;
+		}
+
+		public static Visibility min(Visibility a, Visibility b) {
+			return a.getValue() < b.getValue() ? a : b;
+		}
 	}

+	/**
+	 * The current version of the group format.
+	 */
+	public static final int FORMAT_VERSION = 1;
+
 	private final GroupId id;
 	private final ClientId clientId;
+	private final int majorVersion;
 	private final byte[] descriptor;

-	public Group(GroupId id, ClientId clientId, byte[] descriptor) {
+	public Group(GroupId id, ClientId clientId, int majorVersion,
+			byte[] descriptor) {
 		if (descriptor.length > MAX_GROUP_DESCRIPTOR_LENGTH)
 			throw new IllegalArgumentException();
 		this.id = id;
 		this.clientId = clientId;
+		this.majorVersion = majorVersion;
 		this.descriptor = descriptor;
 	}

@@ -36,6 +59,13 @@ public class Group {
 		return clientId;
 	}

+	/**
+	 * Returns the major version of the client to which the group belongs.
+	 */
+	public int getMajorVersion() {
+		return majorVersion;
+	}
+
 	/**
 	 * Returns the group's descriptor.
 	 */
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupFactory.java
@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 public interface GroupFactory {

 	/**
-	 * Creates a group with the given client ID and descriptor.
+	 * Creates a group with the given client ID, major version and descriptor.
 	 */
-	Group createGroup(ClientId c, byte[] descriptor);
+	Group createGroup(ClientId c, int majorVersion, byte[] descriptor);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupId.java
@@ -15,7 +15,7 @@ public class GroupId extends UniqueId {
 	/**
 	 * Label for hashing groups to calculate their identifiers.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.GROUP_ID";
+	public static final String LABEL = "org.briarproject.bramble/GROUP_ID";

 	public GroupId(byte[] id) {
 		super(id);
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/Message.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/Message.java
@@ -5,6 +5,11 @@ import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LEN

 public class Message {

+	/**
+	 * The current version of the message format.
+	 */
+	public static final int FORMAT_VERSION = 1;
+
 	private final MessageId id;
 	private final GroupId groupId;
 	private final long timestamp;
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageFactory.java
@@ -7,5 +7,7 @@ public interface MessageFactory {

 	Message createMessage(GroupId g, long timestamp, byte[] body);

+	Message createMessage(byte[] raw);
+
 	Message createMessage(MessageId m, byte[] raw);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageId.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageId.java
@@ -16,7 +16,13 @@ public class MessageId extends UniqueId {
 	/**
 	 * Label for hashing messages to calculate their identifiers.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.MESSAGE_ID";
+	public static final String ID_LABEL = "org.briarproject.bramble/MESSAGE_ID";
+
+	/**
+	 * Label for hashing blocks of messages.
+	 */
+	public static final String BLOCK_LABEL =
+			"org.briarproject.bramble/MESSAGE_BLOCK";

 	public MessageId(byte[] id) {
 		super(id);
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncConstants.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncConstants.java
@@ -2,6 +2,8 @@ package org.briarproject.bramble.api.sync;

 import org.briarproject.bramble.api.UniqueId;

+import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
+
 public interface SyncConstants {

 	/**
@@ -10,16 +12,8 @@ public interface SyncConstants {
 	byte PROTOCOL_VERSION = 0;

 	/**
-	 * The length of the record header in bytes.
+	 * The maximum length of a group descriptor in bytes.
 	 */
-	int RECORD_HEADER_LENGTH = 4;
-
-	/**
-	 * The maximum length of the record payload in bytes.
-	 */
-	int MAX_RECORD_PAYLOAD_LENGTH = 48 * 1024; // 48 KiB
-
-	/** The maximum length of a group descriptor in bytes. */
 	int MAX_GROUP_DESCRIPTOR_LENGTH = 16 * 1024; // 16 KiB

 	/**
@@ -40,5 +34,5 @@ public interface SyncConstants {
 	/**
 	 * The maximum number of message IDs in an ack, offer or request record.
 	 */
-	int MAX_MESSAGE_IDS = MAX_RECORD_PAYLOAD_LENGTH / UniqueId.LENGTH;
+	int MAX_MESSAGE_IDS = MAX_RECORD_PAYLOAD_BYTES / UniqueId.LENGTH;
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordReader.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordReader.java
@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.IOException;

@NotNullByDefault
-public interface RecordReader {
+public interface SyncRecordReader {

 	boolean eof() throws IOException;

--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordReaderFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordReaderFactory.java
@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.InputStream;

@NotNullByDefault
-public interface RecordReaderFactory {
+public interface SyncRecordReaderFactory {

-	RecordReader createRecordReader(InputStream in);
+	SyncRecordReader createRecordReader(InputStream in);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordWriter.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordWriter.java
@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.IOException;

@NotNullByDefault
-public interface RecordWriter {
+public interface SyncRecordWriter {

 	void writeAck(Ack a) throws IOException;

--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordWriterFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncRecordWriterFactory.java
@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import java.io.OutputStream;

@NotNullByDefault
-public interface RecordWriterFactory {
+public interface SyncRecordWriterFactory {

-	RecordWriter createRecordWriter(OutputStream out);
+	SyncRecordWriter createRecordWriter(OutputStream out);
 }
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSessionFactory.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/sync/SyncSessionFactory.java
@@ -2,9 +2,9 @@ package org.briarproject.bramble.api.sync;

 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.transport.StreamWriter;

 import java.io.InputStream;
-import java.io.OutputStream;

@NotNullByDefault
 public interface SyncSessionFactory {
@@ -12,8 +12,8 @@ public interface SyncSessionFactory {
 	SyncSession createIncomingSession(ContactId c, InputStream in);

 	SyncSession createSimplexOutgoingSession(ContactId c, int maxLatency,
-			OutputStream out);
+			StreamWriter streamWriter);

 	SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
-			int maxIdleTime, OutputStream out);
+			int maxIdleTime, StreamWriter streamWriter);
 }
--- a/Show More
+++ b/Show More