SecureChat v3.4.1 Beta — PQXDH Post-Quantum + One-Shot Ephemeral Photos

🧪 Beta Release — V3.4.1

Post-Quantum Encryption (PQXDH)

Hybrid key exchange: X25519 + ML-KEM-768 — resistant to quantum attacks

• PQXDH handshake with deferred root key upgrade
• BouncyCastle 1.80 ML-KEM implementation
• DeviceSecurityManager with StrongBox/TEE enforcement
• QR deep link v2 (X25519 + ML-KEM + displayName)

📸 One-Shot Ephemeral Photos

• View-once photos for sender AND receiver
• 2-phase secure deletion (immediate DB flag + delayed file delete)
• Anti-navigation bypass protection (no Handler.postDelayed exploit)

🔏 QR Code Fingerprint Verification

• Toggle between emoji fingerprint and QR code
• SHA-256 hex encoding (64 ASCII chars, no Unicode issues)
• Built-in scanner (same CustomScannerActivity as contact invitation)
• Automatic verification on scan match / MITM warning on mismatch

🔑 Redesigned Restore Screen

• Professional 24-word BIP-39 autocomplete grid (3×8)
• Real-time word counter + visual validation
• Auto-advance on word selection

🎨 UI & Security Improvements

• Send confirmation dialog + progress bar + retry button
• Send indicator ✓ in sent bubbles
• Protocol display: PQXDH · X25519 + ML-KEM-768 · AES-256-GCM · Double Ratchet
• Forgot PIN recovery via mnemonic phrase
• 29 layout audit with fixes
• Independent fingerprint verification (local-only state)
• Room DB v17 (oneShotOpened column)
• New release keystore (RSA 4096, 100-year validity)

Verify integrity

sha256:5e1a9a6249f1582eef80f91021805598b17e1a9d6ef6e136041dd5040aa1a414  SecureChat-v3.4.1-beta.apk

⚠️ Beta — for testing only. May be removed at any time.

New keystore — uninstall previous beta before installing this APK.