One pivotal move in this direction involves Chrome’s support for the X25519Kyber768 hybrid key exchange, which aids in establishing symmetric secrets within Transport Layer Security (TLS). This support is set to be introduced in version 116 of the Chrome browser, with the option also accessible through a flag in Chrome 115.
The X25519Kyber768 hybrid exchange amalgamates two cryptographic components: X25519 and Kyber768. While the former is a key-agreement mechanism already utilized in TLS, the latter represents a quantum-resistant Key Encapsulation Method (KEM). Kyber768 is one of the cryptographic algorithms identified as quantum-resistant by the National Institute of Standards and Technology (NIST).
By integrating support for X25519Kyber768, Chrome aims to identify and address any potential compatibility challenges well ahead of quantum computers becoming operational outside laboratory environments. Furthermore, this updated key agreement will be employed when connecting to third-party server operators, such as Cloudflare, that are incorporating similar support.
