Cloudflare IPsec Adds Post-Quantum Hybrid ML-KEM Encryption

Cloudflare has made post‑quantum encryption in its IPsec product generally available, moving its target for full post‑quantum security to 2029 in response to recent quantum‑computing advances. The new implementation uses the hybrid ML‑KEM (FIPS 203) draft‑ietf‑ipsecme‑ikev2‑mlkem, combining a classical Diffie‑Hellman exchange with ML‑KEM to stop harvest‑now‑decrypt‑later attacks. Interoperability tests have confirmed that Fortinet FortiOS 7.6.6+ and Cisco 8000 Series Secure Routers 26.1.1+ can now establish post‑quantum Cloudflare IPsec tunnels using the same draft. Cloudflare IPsec’s hybrid handshake runs first with Diffie‑Hellman, then encrypts a second ML‑KEM exchange, and mixes both outputs into the session keys for ESP traffic. The draft was published in late 2025, roughly four years after its TLS counterpart landed, and the implementation was previously in closed beta.

This release means that customers can protect their WAN against quantum‑era attacks today using existing hardware, without waiting for new cryptographic standards or specialized equipment. The move also aligns with Cloudflare’s broader post‑quantum roadmap, which now includes a 2029 target for full network‑wide post‑quantum security.

The announcement also highlights the importance of interoperable standards, noting that earlier RFC 9370 implementations suffered from ciphersuite bloat and limited interoperability, whereas the new draft resolves these gaps.