Security Architecture
Built upon the battle-tested Signal Protocol with cutting-edge post-quantum cryptography. Every message, every file, every call — protected by design, not promise.
Encryption Protocol Stack
Our multi-layered security architecture ensures that no single point of failure can compromise your privacy.
Application Layer
User-facing security controls • Biometric locks • Screen security
Session Layer
Double Ratchet Algorithm • X3DH Key Agreement • Sesame Multi-device
Cryptographic Layer
Curve25519 • AES-256-GCM • HMAC-SHA256 • PQXDH (Kyber-1024)
Infrastructure Layer
TLS 1.3 • Certificate Pinning • Sealed Sender • Zero-Knowledge Design
Signal Protocol Implementation
The gold standard in end-to-end encryption, trusted by billions worldwide.
Extended Triple Diffie-Hellman (X3DH)
Establishes shared secret keys between parties who have never met, with built-in deniability and forward secrecy from the first message.
- Asynchronous key agreement
- Cryptographic deniability
- No trusted third party
Double Ratchet Algorithm
The heart of Signal Protocol. Combines a symmetric-key ratchet with a Diffie-Hellman ratchet to provide fresh keys for every message.
- Per-message key derivation
- Perfect forward secrecy
- Break-in recovery
Post-Quantum X3DH (PQXDH)
Future-proof protection against quantum computers. Combines traditional elliptic curve cryptography with lattice-based Kyber-1024.
- Harvest-now-decrypt-later defense
- NIST standardized (Kyber)
- Hybrid security model
Sesame Algorithm
Seamlessly manage multiple devices per user while maintaining end-to-end encryption guarantees across all sessions.
- Device-to-device encryption
- Session continuity
- Transparent key management
We Know Nothing
Our servers never see your messages, contacts, or metadata. We can't read your data — and neither can anyone else.
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Sealed Sender
Message headers are encrypted. We don't know who you're talking to.
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Encrypted Group Info
Group names, members, and conversations are encrypted. We can't see your team structure.
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Private Notes & Nicknames
Your custom notes and nicknames for contacts stay on your device. We never see them.
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Local Preferences
Mute settings, notification preferences, and all personal configurations are stored locally.
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Client-Side Encryption
All encryption happens on your device. Keys never leave your control.
Cryptographic Primitives
Battle-tested algorithms reviewed by the world's leading cryptographers.
AES-256-GCM
Symmetric encryption for message content. NIST-approved, hardware-accelerated.
Curve25519
Elliptic curve for key agreement. Fast, safe from timing attacks.
HMAC-SHA256
Message authentication code. Ensures integrity and authenticity.
Kyber-1024
NIST post-quantum standard. Lattice-based key encapsulation.
Ed25519
Digital signatures. Non-repudiation and authentication.
HKDF-SHA256
Key derivation function. Extracts cryptographic keys from sources.
Security Audits & Compliance
Independently verified. Publicly documented. Continuously tested.
Third-Party Audits
Regular security assessments conducted by independent third-party organizations.
Open Protocols
Built upon industry-standard, publicly audited Signal Protocol. Published specifications ensure cryptographic transparency.
View SpecificationsContinuous Security
Our security team monitors for new vulnerabilities and applies updates to stay ahead of emerging threats.
Ready for Uncompromising Security?
Join thousands of privacy-conscious teams who trust Xipha with their most sensitive communications.