December 6, 2023

Sign is getting ready for a quantum computing world, unveiling a brand new protocol designed to be proof against quantum computer systems.

Quantum computing is a revolutionary advance in computing, one which threatens to out of date current encryption and safety requirements. Sign, some of the safe messaging platforms, is already engaged on a brand new protocol designed for the quantum period.

The corporate introduced the event in a weblog put up:

At present we’re comfortable to announce step one in advancing quantum resistance for the Sign Protocol: an improve to the X3DH specification which we’re calling PQXDH. With this improve, we’re including a layer of safety towards the specter of a quantum laptop being constructed sooner or later that’s highly effective sufficient to interrupt present encryption requirements.

Sign goes on to spotlight the brand new measures:

To handle this downside, new post-quantum cryptosystems have been created to implement new one-way capabilities that can not be advantageously reversed by a quantum laptop. Because of innovation from cryptographic researchers and the NIST Standardization Course of for Put up-Quantum Cryptography we now have secure choices which have been created and vetted by a big group of consultants.

The corporate shouldn’t be relying solely on the brand new protocol, however utilizing a mixture of each:

We imagine that the important thing encapsulation mechanism we now have chosen, CRYSTALS-Kyber, is constructed on strong foundations, however to be protected we don’t wish to merely substitute our current elliptic curve cryptography foundations with a post-quantum public key cryptosystem. As a substitute, we’re augmenting our current cryptosystems such that an attacker should break each techniques with a purpose to compute the keys defending individuals’s communications.

The essence of our protocol improve from X3DH to PQXDH is to compute a shared secret, knowledge recognized solely to the events concerned in a personal communication session, utilizing each the elliptic curve key settlement protocol X25519 and the post-quantum key encapsulation mechanism CRYSTALS-Kyber. We then mix these two shared secrets and techniques collectively in order that any attacker should break each X25519 and CRYSTALS-Kyber to compute the identical shared secret.

The brand new protocol is already carried out within the newest model of Sign.

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