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flamenet-messenger-android/SECURITY.md
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Paul HittandClaude Opus 5 41cdef5e07 docs: drop dated self-corrections
Remove dates and "this used to say X" framing from prose and comments.
What the tree does now is the only thing that matters; the history is in
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Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-09 09:30:32 -04:00

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# Security
## Reporting a vulnerability
Email **security@flamenetmessenger.com**. Please do not open a public issue for
anything affecting confidentiality or authentication. We acknowledge within 72
hours.
## Status
**Not independently audited.** This Android app has been reviewed in-house and
is covered by the JVM unit suites plus on-device instrumentation, alongside the shared 253-check relay conformance suite and
cross-platform interop tests that run the real engine on both sides.
An internal adversarial audit found and fixed a family of
sender-attribution flaws: the ratchet authenticates a *device*, and the user id
inside a sealed envelope is a claim its author chooses, the two were not bound.
Devices now bind to their user on first proven use, control traffic (delivery
keys, avatars) is refused from an unproven sender, and the key-transparency log
head is verified against a pinned issuer key. Finding that class of bug in-house
is a reason to expect more from outside review, not fewer.
## What the app protects, and what it cannot
Private keys are generated on the device and live in the Android Keystore, which never hands out key material. Message history is
sealed at rest. The app defends against a **malicious or compromised relay**
reading messages, and against a passive adversary recording traffic to decrypt
after a quantum computer exists (when both ends publish a post-quantum
identity, the safety number says which guarantee it covers).
It does **not** defend against:
- **A compromised device.** Malware with your unlock reads plaintext. The app
lock is a speed bump against someone holding your unlocked phone, not
encryption.
- **Metadata.** The relay sees who is addressed and when. Sealed sender removes
the sender from the stored row, not from the network connection.
- **Your correspondent.** Anything you send can be screenshotted, kept, or
repeated by the person you sent it to.
## Verifying what you run
Every byte of the shipped APK's contents reproduces from this source; only the
randomized signing block differs. See `docs/REPRODUCIBLE.md` in the relay repo
and `scripts/verify-build.py` in the Android repo.