How enterprise site-to-site tunnels and remote-access VPNs are being upgraded to resist harvest-now-decrypt-later espionage using post-quantum key encapsulation.
Adversaries and nation-state intelligence agencies intercept and record terabytes of encrypted VPN traffic traversing international fiber cables every day. Once cryptanalytically relevant quantum computers are built, recorded classical Diffie-Hellman and IKE handshakes will be decrypted retroactively. Retrofitting VPNs is the single highest-priority enterprise defense.
WireGuard's Noise IK handshake is exceptionally fast but relies on Curve25519. We examine experimental and standardized hybrid extensions—such as the Rosenpass protocol—that exchange an out-of-band ML-KEM key every few minutes, injecting fresh post-quantum entropy into WireGuard's symmetric ratchets.
IETF RFC 9370 allows IPsec IKEv2 to perform multiple sequential or parallel key exchanges. We detail how enterprise gateways negotiate classical Diffie-Hellman alongside ML-KEM-1024, deriving compound session keys that satisfy both NIST and CNSA 2.0 standards.