Sam Blackshear, co-founder and chief technology officer of Mysten Labs, the creator of the Sui blockchain, is stepping down to join Anthropic to work on defensive security research. Mysten Labs co-founder and CEO Evan Cheng will set the “technical vision” for Mysten going forward. Blackshear co-founded Mysten Labs in September 2021 with four former Meta executives. He said he is motivated to work on security at a time when the balance of power between attackers and defenders is shifting, as AI is increasingly used to identify software vulnerabilities, automate phishing campaigns, and accelerate attacks on blockchain infrastructure. In April, Blackshear hosted a panel about how AI coding agents are reshaping smart contract security. He described a turning point when he used Claude to port a static analysis tool he built at Facebook to Move, the programming language for Sui smart contracts, and it flagged potential vulnerabilities. He said the triage results were completely manual before, and the coding would have taken a long time. Many crypto firms are seeking access to powerful AI models, which are restricted to a small group of companies. Crypto executives agreed that restricting frontier models makes sense initially but not once competing, publicly available AI models reach the same cybersecurity capability.