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Relabel private Nostr envelopes honestly

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jack
2026-07-10 17:22:24 -04:00
parent 733098bb63
commit cc32f0b596
28 changed files with 1161 additions and 474 deletions
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PRIVACY_POLICY.md
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@@ -73,7 +73,7 @@ Private group members receive the group's name, roster, key epoch, and encrypted
Internet-backed features are optional. When enabled or used:
- Private fallback messages use encrypted NIP-17 gift wraps. Relays can observe event and network metadata but not the message plaintext.
- Private fallback messages use BitChat's app-specific encrypted envelopes. This format is not NIP-17, NIP-44, or NIP-59 compatible. Relays can observe the recipient public-key tag, event timing and size, and network metadata, but not the message plaintext or stable sender identity.
- Public location-channel messages, notes, notices, and presence include a geohash tag, event kind, timestamp, and a public key. A geohash reveals an approximate area; finer precision reveals a smaller area.
- The optional mesh bridge publishes bridge-enabled public mesh messages and presence to a neighborhood rendezvous cell. Those messages are public to participants and relays for that cell. A per-message “nearby only” choice prevents that message from crossing the bridge.
- Bridge courier drops contain opaque end-to-end encrypted envelopes and a rotating recipient tag. Relays still observe timing and network metadata.
@@ -103,7 +103,7 @@ Private and public features use different protections:
- Mesh private sessions use Noise XX with X25519, ChaCha20-Poly1305, and SHA-256.
- Private group messages use ChaCha20-Poly1305; group state and relevant mesh packets use Ed25519 signatures.
- Nostr events use secp256k1 Schnorr signatures. NIP-44 v2 private payloads use secp256k1 key agreement, HKDF-SHA256, and XChaCha20-Poly1305.
- Nostr events use secp256k1 Schnorr signatures. BitChat private envelopes use secp256k1 key agreement, HKDF-SHA256 with a BitChat-specific domain separator, and XChaCha20-Poly1305. The envelope format is proprietary, only interoperates with BitChat clients, and does not provide forward secrecy against later compromise of the recipient's static Nostr private key.
- The persistent private-message outbox uses ChaCha20-Poly1305 with a key held in the keychain. Some other protected local identity state uses AES-GCM.
- Public mesh, bridge, geohash, and board content is signed or authenticated as appropriate but is intentionally not confidential.