Google DeepMind just mathematically verified key parts of Signal

Google DeepMind researchers used agentic AI and a new framework called AlphaProof Code to formally verify a number of the Signal protocol's key cryptographic guarantees in a four-week proof-of-concept project. The analysis found no new vulnerabilities in the portions it examined, but when applied to older Signal versions with known, long-fixed flaws, AlphaProof Code correctly identified them and showed the protocol could not be formally verified. DeepMind researchers say the work is one milestone and that scaling formal verification to all software remains a long way off.