GOOGLE'S AI WROTE 6 MILLION LINES OF MATH PROOF — AND CHECKED SIGNAL'S ENCRYPTION

Google DeepMind said on November 10 that its AlphaProof Code system formally verified key security properties of the actual code behind the Signal protocol — the encryption protecting billions of private conversations in Signal and Google Messages. Agents powered by Gemini Carbon generated over six million lines of Lean proof in four weeks, work DeepMind says would historically take expert teams years.

The proof covers the post-quantum handshake and Triple Ratchet for one-to-one sessions, down to compiled machine code — and when DeepMind reintroduced two previously fixed bugs, the system proved the buggy versions insecure. The scope is narrow and stated: not group chats, not the whole app. The artifacts are open-sourced.