From c8dd80a3d18d6875f1f7bfacdc867809f2657831 Mon Sep 17 00:00:00 2001 From: Torsten Grote Date: Fri, 29 Nov 2019 13:02:57 +0000 Subject: [PATCH] Create FAQ --- FAQ.md | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 FAQ.md diff --git a/FAQ.md b/FAQ.md new file mode 100644 index 0000000..5015feb --- /dev/null +++ b/FAQ.md @@ -0,0 +1,37 @@ +List of questions: + +[[_TOC_]] + +# Will there be an iOS version of Briar? + +Short answer: Probably not. + +Long answer: [We're looking into whether an iOS version is feasible](https://code.briarproject.org/briar/briar/issues/445). +Briar needs to run in the background to receive messages from contacts, and iOS has +much tighter **restrictions on background apps** than Android (though +Android's getting stricter). + +A typical iOS messaging app would use a push notification to wake the +app when a message is received, but this exposes metadata to Apple's +push notification service and the app developer's push gateway. + +To reduce the metadata leakage, the sender of the message could connect +to the push gateway via Tor - but the push gateway and APNS would still +know who was receiving the notification. In a publish-subscribe network +like Briar, if a bunch of people always receive notifications whenever +the Revolutionary Planning Council updates its blog, then even if we +don't know who sent the notifications, we've learned something sensitive +about the recipients. + +If we don't use push notifications then the best Apple allows us to do +is wake up every 15 minutes and check for messages. But maybe the sender +won't be online when we check (their 15 minute intervals might not be +aligned with ours - clocks aren't perfect). So we need somewhere for the +sender to store the message until our next check. + +We're working on a piece of software called a mailbox that will receive +encrypted messages over Tor and store them until the owner collects +them. It's designed to run on a spare Android device, laptop, or +Raspberry Pi that's plugged into power and internet. Once that's ready +it will make an iOS app more feasible. But we are not sure if the 15 minute +delay will be a deal-breaker. \ No newline at end of file