Quantum Secure Tunneling Protocol: a post-quantum secure tunneling protocol for certificate-authenticated encrypted sessions and VPN-class transport.

Browser-based downgrade demo — RFC 8446. Strip X25519MLKEM768 from the ClientHello and watch two PQ-capable endpoints agree on bare X25519. Success is the alarm. Negotiation happens before authentication — the fix isn't detection, it's binding the transcript into the key. FREAK and Logjam were this shape. No backends.

Quantum Secure Messaging Protocol Simplex: a post-quantum one-way secure messaging protocol for authenticated encrypted sessions with replay resistance and transcript-bound key establishment.

Dual Key Tunneling Protocol: a post-quantum secure-channel design using KEM entropy, directional PSKs, transcript binding, and ratcheted tunnel state.

Symmetric Authenticated Tunneling Protocol: a certificate-free secure tunnel protocol using deterministic key hierarchies, cost-based authentication, and authenticated encryption.

Quantum Secure Messaging Protocol Duplex: a post-quantum bidirectional messaging protocol for authenticated encrypted sessions with replay resistance and transcript-bound key establishment.