DeepMind's AlphaProof Code Verifies Signal's Cryptographic Core

Google DeepMind unveiled AlphaProof Code, an AI system that mathematically proves software meets its security specifications, and used it to verify the cryptographic core code running on Signal users' devices 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 and flagged roughly one percent of the codebase for human review, catching two deliberately planted bugs immediately. Signal CTO Ehren Kret said 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.

Google DeepMind completed a four-week project that mathematically verified key parts of Signal, according to Ars Technica. The work hints that AI could make formal verification far more practical, though the report provides no further technical details.