Signal improved its protocol to prepare encrypted messaging for the quantum era.

They call the improvement “Triple Ratchet” (or SPQR = Signal Post-Quantum Ratchet).

Signal Protocol and Post-Quantum Ratchets

We are excited to announce a significant advancement in the security of the Signal Protocol: the introduction of the Sparse Post Quantum Ratchet (SPQR). This new ratchet enhances the Signal Protocol’s resilience against future quantum computing threats while maintaining our existing security guar…

Signal Messenger

If history repeats itself, this could become the next open standard for secure messaging.

Signal (formerly Open Whisper Systems) created the Double Ratchet protocol in 2013–2014, introduced in TextSecure v2 in February 2014. They packaged it into the open source Signal Protocol. It became the mainstream standard for end-to-end encrypted messaging. XMPP adopted it (OMEMO, developed in 2015). Matrix adopted it (Olm/Megolm implements Double Ratchet concepts).

The problem is that current encryption methods could break when quantum computers get powerful enough, so Signal built Triple Ratchet to protect against that.

Most messaging companies are preparing for this but I noticed that WhatsApp has no public roadmap for the adoption of quantum resistance protocols. They use the Signal Protocol for encryption, so they may simply wait for the result of Signal’s work to adopt the new approach.

It is much heavier to implement, so I am wondering if Triple Ratchet follows the same path as Double Ratchet and gets widespread adoption.

If open protocols like XMPP and Matrix adopt it, it may be huge for European messaging independence.

What’s your take? Do you think quantum resistance will become a mandatory feature for end-to-end encrypted messaging platforms in the next couple of years?