TLS
Transport Layer Security
The protocol securing most internet traffic. TLS is the furthest-advanced post-quantum migration in practice: hybrid key exchange combining X25519 with ML-KEM-768 is already enabled by default across major browsers and CDNs.
Related terms
Combining a classical algorithm with a post-quantum one so the result stays secure as long as either component holds. It hedges against both a future quantum attack and an undiscovered flaw in the newer post-quantum scheme.
The NIST-standardised post-quantum key encapsulation mechanism, used to establish a shared secret over an untrusted network. It is the replacement for RSA key transport and elliptic-curve Diffie-Hellman.
The practice of recording encrypted traffic today in order to decrypt it once a quantum computer becomes available. It is the one quantum risk already in progress, and it makes long-life confidential data the first migration priority.