Encryption Pipeline

Step through Zero Protocol's cryptographic pipeline — key generation, ECDH exchange, HKDF derivation, AEAD encryption, and post-quantum encapsulation.

Zero Protocol · Crypto Pipeline

Encryption Flow

Zero Protocol uses a multi-step cryptographic pipeline combining classical elliptic-curve primitives with post-quantum key encapsulation for forward-secret, quantum-resistant encrypted tunnels.

Stage 1 / 6

Key Gen

Ed25519 + X25519 key pair generated from secure entropy.

Classical Primitives

Elliptic-Curve Suite

Key agreement: X25519 (Curve25519 ECDH)
Signing: Ed25519
KDF: HKDF-SHA256
AEAD: ChaCha20-Poly1305
MAC: BLAKE2b-256

Post-Quantum

ML-KEM-768 (Kyber)

Algorithm: ML-KEM-768 (FIPS 203)
Security: NIST PQC Level 3
Ciphertext: 1 088 B per hop
Shared secret: 32 B
Hybrid mode: ECDH ⊕ KEM (both must break)

Quantum-safeHybrid

Pipeline Stages

1
Key Generation
Ed25519 + X25519 pairs created from OS entropy (/dev/urandom).
2
Key Exchange
Ephemeral X25519 ECDH at each hop. Shared secret never leaves the session.
3
KDF Expansion
HKDF-SHA256 with per-hop salt produces Kenc (encryption) and Kmac (authentication).
4
AEAD Encryption
ChaCha20-Poly1305 encrypts and authenticates in one pass. Nonce derived from circuit ID.
5
PQ Encapsulation
ML-KEM-768 encapsulates a second 32-byte secret. Final key = HKDF(ECDH secret || KEM secret).
6
Forward Secrecy
All ephemeral keys zeroized on circuit teardown. Session cannot be decrypted retroactively.

Privacy Level Crypto

L1Raw — no encryption layer

L2Obfs4-Lite XOR obfuscation

L3Sphinx + TLS 1.3 morph (default)

L4Sphinx + max jitter + cover traffic