Post-quantum SSH keys: prep for BIP-360 and Kyber
Post-quantum security for SSH in 2026: Kyber-768 support, BIP-360 discussion and hybrid keys. Shore up keys now while the cost of change is low.
Store now, decrypt later is the threat, and SSH keys are sitting on the wire today. Quantum-capable adversaries are already harvesting encrypted sessions in the hope of breaking them later — which is why hybrid options knell: Kyber-768 key exchange in OpenSSH 9.x and the quantum-resistant address formats under discussion as BIP-360 on Bitcoin.
What is already practical in 2026
- ▹OpenSSH hybrid KEX: default post-quantum key exchange (mlkem768x25519) in recent releases.
- ▹FIPS 203 / ML-KEM: Kyber ratcheted into the standardisation pipeline.
- ▹BIP-360: an evaluated proposal for quantum-resistant Bitcoin address formats — not yet consensus.
- ▹Auditing: worth your time now; migration costs rise the longer you wait.
Step to take today
Update OpenSSH on your servers, enable the hybrid algorithm, rotate old Ed25519 keys once to a hardened configuration, and keep a hardware-backed copy of everything you still encrypt. Five minutes now is dramatically cheaper than a migration under pressure.