Hybrid TLS Key Exchange

The X25519MLKEM768 hybrid that now protects the majority of browser TLS traffic — classical and post-quantum security welded together.

Core Principles & Analysis

• Hybrid construction means an attacker must break both X25519 and ML-KEM to recover the session key.
• Chrome enabled it by default in 2024; major CDNs terminated post-quantum handshakes the same year.
• The larger ClientHello briefly exposed middlebox bugs across the internet — the cost of moving first.

Specifications & Metrics

• PLATFORM: Chrome, Firefox, Cloudflare, Google
• MECHANISM: X25519 + ML-KEM-768
• SINCE: 2024