Frédéric Jacobs💬🔒⚛️ Delighted to announce iMessage PQ3, our formally-verified protocol for end-to-end encryption that provides the strongest post-quantum protections against “Harvest Now, Decrypt Later” attackers by not only performing a quantum-secure key establishment, but also performing post-quantum ongoing rekeying.
Support for PQ3 will start to roll out with the public releases of iOS 17.4, iPadOS 17.4, macOS 14.4, and watchOS 10.4
https://security.apple.com/blog/imessage-pq3/
Blog - iMessage with PQ3: The new state of the art in quantum-secure messaging at scale - Apple Security Research
We are introducing PQ3, a groundbreaking cryptographic protocol for iMessage that advances the state of the art of end-to-end secure messaging. With compromise-resilient encryption and extensive defenses against even highly sophisticated quantum attacks, PQ3 provides protocol protections that surpass those in all other widely deployed messaging apps.
Jad Osseiran