SIGNAL PROTOCOL AND POST-QUANTUM RATCHETS

Summary from the TLDR Dev newsletter

Signal is upgrading its protocol to the Triple Ratchet, incorporating the Sparse Post-Quantum Ratchet (SPQR) alongside the existing Double Ratchet. This improves security against future quantum computing threats. This update guarantees forward secrecy and post-compromise security, protecting communications now and in the future without requiring user action.