Beware: New QUIC / Kyber768 ("Quantum-Resistant Mechanism") is broken + workaround to disable it in Chrome 124.

[D.Draker]

"Kyber (Quantum-Resistant Mechanism) in Chrome 124 Leads to Web Connection Problems"

by Luke Jones

"Impact on Connectivity and Responses

The introduction of the Kyber768 quantum-resistant key agreement algorithm, intended for TLS 1.3 and QUIC connections, has inadvertently caused connectivity issues. System administrators have reported on Reddit and other platforms that web applications, firewalls, and servers are dropping connections following the ClientHello TLS handshake."

"To address these connectivity problems, Google has provided a temporary workaround. Users experiencing issues can disable the TLS 1.3 hybridized Kyber support in Chrome by adjusting the browser's flags. Similarly, administrators have the option to disable the PostQuantumKeyAgreementEnabled policy."

Source:

https://winbuzzer.com/2024/05/02/google-chrome-124-launches-with-quantum-resistant-encryption-causes-connectivity-issues-xcxwbn/