Receive encrypted messages while Briar is offline
About this app
Briar Mailbox is a helper app for Briar messenger (https://f-droid.org/packages/org.briarproject.briar.android/) that lets you receive encrypted messages from your contacts while Briar is offline.
Next time Briar comes online it will automatically fetch the messages from your Mailbox.
Install the Mailbox app on a spare device, link it with your Briar account, and leave it connected to power and Wi-Fi.
Licensed under AGPL-3.0-or-later.
What's New in v1.0.9
Imported from the F-Droid repository index.
Version history
Aug 12, 2024 · 51.3 MB · Android API 18–33 · code 10009
Imported from the F-Droid repository index.
SHA-256 6251ab38cf7c79b3b8e970686e39e0a41078d6a0ecbce32000f3d4d0b5596245
Apr 12, 2024 · 42.6 MB · Android API 18–33 · code 10008
Imported from the F-Droid repository index.
SHA-256 87a9ada0d95ee5088c7a74d67379439df7b96df68c9e2b68365c3f1c407c8927
Will it run on your device?
87%
- Runs on a broad range of modern Android versions.
- Multiple CPU architectures are covered.
Installation Guide
Open Settings on your Android device
Go to Security → Unknown sources (or Install unknown apps)
Enable "Allow from this source" for your browser or file manager
Open the downloaded APK file from your Downloads folder
Tap "Install" and wait for installation to complete
Launch the app from your home screen
Make sure to re-enable Unknown Sources restrictions after installation for security.
How to install this safely
How to verify the file you downloaded
Before you install anything, confirm the file is the one described here. On a computer, run shasum -a 256 your-download.apk (macOS or Linux) or certutil -hashfile your-download.apk SHA256 (Windows), then compare the output character-for-character with the SHA-256 on this page. If a single character differs, the file is not the build we recorded — delete it.
What the signing certificate proves
Every Android app is signed with a private key that only its developer holds. The fingerprint on this page is a hash of the matching public certificate, and it proves continuity rather than identity: it tells you a build came from whoever signed the earlier ones. Android enforces this at install time — if a package claiming to be org.briarproject.mailbox is signed with a different key, the system will refuse to install it over your existing copy. A fingerprint that changes between releases is worth pausing on, because a repackaged app that has been modified by someone else cannot keep the original signature.
How to roll back to an earlier version
If the current release misbehaves, 1.0.8 is the last build before it. Android will not install an older version code over a newer one, so you must uninstall Briar Mailbox first — which clears its local data unless you have a backup. Reinstall the older APK only if its signing fingerprint matches the build you already trust, and check the API range: an older release may target an Android version your device has moved past.
Why we list sources instead of hosting everything
The official store channel is almost always the right choice: it updates automatically and carries the publisher's own distribution guarantees. A direct APK is useful when a device has no store access, when a rollout has not reached your region, or when you need a specific version — and only when the publisher has authorized that copy. APKBrowse does not list pirated, cracked, or unauthorized rebuilds of Briar Mailbox, and a listing is removed when the evidence for it stops holding up.
Get Briar Mailbox
Every source we list for org.briarproject.mailbox is legality-reviewed. Pirated or cracked builds are never offered.
Other sources
F-Droid listing
officialF-Droid builds this app from source and signs it. This is its official listing, with older builds and full release notes.
Source code
verified publisherThe upstream repository this build is compiled from.
We check legality and signature continuity, but device behaviour still varies. Install at your own discretion.
App Information
Security Verification
We record provenance; we do not run malware scans. Verify the hash yourself before installing.
SHA-256 Hash
6251ab38cf7c79b3b8e970686e39e0a41078d6a0ecbce32000f3d4d0b5596245
Signing certificate
acc4dba48bea4c14df80361a68e5607c0bdbe4ddfafff60cf5ca6c09190f6b83
Permissions Required
Previous Versions
The signing certificate fingerprint for this release is on record, so a build that does not match it did not come from this publisher.
Report a problem with this listing
A listing is only as good as its corrections. If a source is broken, a signature looks wrong, or this app should not be here, tell the moderation team.