diff --git a/bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java b/bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java
index b6d082098..e74e19921 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java
@@ -153,4 +153,15 @@ public class StringUtils {
 		return new String(c);
 	}
 
+
+	public static String getRandomBase32String(int length) {
+		char[] c = new char[length];
+		for (int i = 0; i < length; i++) {
+			int character = random.nextInt(32);
+			if (character < 26) c[i] = (char) ('A' + character);
+			else c[i] = (char) ('2' + (character - 26));
+		}
+		return new String(c);
+	}
+
 }
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkInputActivity.java b/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkInputActivity.java
index 46b8446e2..79c5aa5da 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkInputActivity.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkInputActivity.java
@@ -113,7 +113,8 @@ public class ContactLinkInputActivity extends BriarActivity
 	}
 
 	private boolean isBriarLink(CharSequence s) {
-		return s.length() == 72 && s.toString().startsWith("briar://");
+		String regex = "^briar://[A-Z2-7]{64}$";
+		return s.toString().trim().matches(regex);
 	}
 
 	private void updateAddButtonState() {
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkOutputActivity.java b/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkOutputActivity.java
index 339ebae5c..05aa748d7 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkOutputActivity.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/contact/ContactLinkOutputActivity.java
@@ -19,7 +19,7 @@ import javax.annotation.Nullable;
 import static android.content.Intent.ACTION_SEND;
 import static android.content.Intent.EXTRA_TEXT;
 import static android.widget.Toast.LENGTH_SHORT;
-import static org.briarproject.bramble.util.StringUtils.getRandomString;
+import static org.briarproject.bramble.util.StringUtils.getRandomBase32String;
 
 public class ContactLinkOutputActivity extends BriarActivity {
 
@@ -39,7 +39,7 @@ public class ContactLinkOutputActivity extends BriarActivity {
 			ab.setDisplayHomeAsUpEnabled(true);
 		}
 
-		String link = "briar://" + getRandomString(64);
+		String link = "briar://" + getRandomBase32String(64);
 
 		TextView linkView = findViewById(R.id.linkView);
 		linkView.setText(link);