CECPQ1
In cryptography, CECPQ1 is a post-quantum cipher developed by Google to make web browsers secure via Transport Layer Security. It was succeeded by CECPQ2.Details
CECPQ1 was designed to provide confidentiality even against an attacker who possesses a large quantum computer. It is a key-agreement algorithm plugged into TLS that combines X25519 and NewHope, a ring learning with errors primitive. Even if New Hope turns out to be breakable, the X25519 key-agreement will ensure that it provides at least the security of our existing connections.
It was available in Google Chrome 54 beta. In 2016, the experimental use in Chrome ended and it was planned to disable CECPQ1 in a later Chrome update.
In CECPQ1, 32 bytes of shared secret material are derived using X25519 key exchange, with a further 32 bytes being derived using the newhope lattice-based key exchange method. The resulting bytes are concatenated and form a pre-master secret for deriving shared keys.
It was succeeded by CECPQ2.
