Security News > 2023 > September > Signal adds quantum-resistant encryption to its E2EE messaging protocol
Signal has announced that it upgraded its end-to-end communication protocol to use quantum-resistant encryption keys to protect users from future attacks.
For communication apps, like Signal, that use end-to-end encryption to protect communication between two parties, the concern is that encrypted communications can be intercepted and deciphered to expose the contents of the communication.
Signal explains that its "X3DH" key agreement protocol has been upgraded to "PQXDH", which incorporates quantum-resistant secret key generation mechanisms for Signal's end-to-end encryption specification.
Specifically, PQXDH uses both X3DH's elliptic curve key agreement protocol and a post-quantum key encapsulation mechanism called CRYSTALS-Kyber.
CRYSTALS-Kyber is a NIST-approved quantum-resistant cryptographic algorithm suitable for general encryption and speedy operations that require a quick exchange of small encryption keys.
"We believe that the key encapsulation mechanism we have selected, CRYSTALS-Kyber, is built on solid foundations, but to be safe, we do not want to simply replace our existing elliptic curve cryptography foundations with a post-quantum public key cryptosystem," explains Signal.