Apple readies iMessage for when quantum computers could break encryption

Apple announced it is upgrading iMessage end-to-end encryption to a post-quantum PQ3 protocol in iOS/iPadOS 17.4, macOS 14.4, and watchOS 10.4, combining elliptic-curve and post-quantum cryptography to mitigate harvest-now-decrypt-later risks. PQ3 will cover new conversations and refresh session keys for older chats, has been reviewed by academic teams, and arrives amid industry moves (e.g., Signal) and policy debates that could impact encryption.