Google Deepmind's AlphaProof Code verified Signal's cryptographic core in four weeks instead of years

Google DeepMind unveiled AlphaProof Code, an AI system that mathematically proves software meets its security specifications, and demonstrated it on Signal's encryption protocol, completing in four weeks work that typically takes years. After experts defined formal security requirements, AI agents built on Gemini Carbon wrote over six million lines in the Lean proof language, flagging roughly one percent of the codebase for human review, and two deliberately planted bugs were caught immediately. Signal CTO Ehren Kret says the approach strengthens trust in data privacy as AI threats grow, and DeepMind plans to extend the method to power grids and medical devices through systems like CodeMender.