Key Agreement (1:1)

X3DH

Extended Triple Diffie-Hellman with ephemeral keys for Perfect Forward Secrecy

Message Ratchet

Double Ratchet

Unique encryption key generated for every single message - compromise of one reveals nothing else

Message Encryption

AES-256-GCM

Authenticated encryption - tampered messages are automatically rejected

Group Encryption

Sender Keys

Per-group encryption chain that rotates automatically when members leave

File Encryption

Double-Layer AES-256-GCM

Per-file random key + conversation key wrapping - even file names are encrypted

اشتقاق المفتاح

HKDF-SHA256

Unique conversation key derived per group - following RFC 5869

تجزئة كلمة المرور

Argon2id

Memory-hard password hashing - winner of the Password Hashing Competition

Transport Security

TLS 1.3 Only

Certificate pinning enforced - man-in-the-middle attacks are blocked at the transport layer

تشفير قاعدة البيانات المحلية

AES-256 Encrypted

Device database fully encrypted at rest with hardware-derived key material

Private Key Storage

Hardware-Backed Keychain

Private keys stored in hardware security module - never leave the secure chip

Two-Factor Authentication

TOTP (RFC 6238)

Time-based one-time passwords as a mandatory second factor

Random Number Generation

OS-Native CSPRNG

Cryptographically secure random number generation via OS hardware