Core engineering and protocols for Hybrid TLS 1.3 Deployment.
While FIPS 203 ML-KEM has undergone exhaustive cryptanalytic review, enterprise and government security policies mandate hybrid key exchange during the transition decade. By combining classical X25519 with ML-KEM-768, the connection remains unconditionally secure against harvest-now-decrypt-later adversaries, even if unexpected mathematical breakthroughs compromise one of the algorithms.
Injecting post-quantum public keys expands the TLS ClientHello beyond typical network MTU boundaries (1,500 bytes), causing IP fragmentation that buggy legacy middleboxes and firewalls often drop. MLKEMSecure implements TCP MSS clamping, optimized extension packing, and HelloRetryRequest handling to guarantee reliable global handshake traversal.