Compatibility Lab

/* X25519Kyber768 is a TLS/QUIC network-stack behavior - not a JS API. */ /* The hybrid key exchange happens automatically in the handshake when Chrome and the server both support it. JavaScript cannot observe the selected TLS NamedGroup, KEM, ClientHello, or enterprise policy state. */ /* What you CAN probe from JS: */ // 1. WebCrypto X25519 support for application-layer key agreement async function hasX25519() { try { await crypto.subtle.generateKey({ name: 'X25519' }, false, ['deriveKey']); return true; } catch { return false; } } // 2. WebCrypto ECDH support for application-layer key agreement async function hasECDH() { try { await crypto.subtle.generateKey({ name: 'ECDH', namedCurve: 'P-256' }, false, ['deriveKey']); return true; } catch { return false; } } // 3. Read the Resource Timing protocol token // This reports values like "h2", "h3", or "http/1.1". It is not a TLS // version, NamedGroup, or KEM detector. function getApplicationProtocol() { const entries = performance.getEntriesByType('navigation'); if (entries.length && entries[0].nextHopProtocol) { return entries[0].nextHopProtocol; } return 'unknown'; } /* For TLS, Chrome handles the hybrid KEM below the web platform. For application-layer post-quantum security, use a web-exposed post-quantum primitive when the platform provides one. */