iMessage PQ3

Apple's post-quantum messaging protocol, adding ongoing rekeying so even a compromised session heals itself.

Core Principles & Analysis

• Goes beyond initial key establishment: fresh post-quantum secrets are woven in as conversations continue.
• Apple described it as 'Level 3' messaging security, a taxonomy it coined for the launch.
• Rolled out to over a billion devices with iOS 17.4.

Specifications & Metrics

• PLATFORM: Apple iMessage
• MECHANISM: Kyber hybrid with periodic rekeying
• SINCE: 2024