Mysten Labs cofounder and chief technology officer Sam Blackshear said on Aug. 6 that he is leaving the Sui developer to join Anthropic for defensive security research.
Summary
- Sam Blackshear is leaving Mysten Labs to join Anthropic for defensive security research involving AI.
- Evan Cheng will assume Mysten’s technical vision while continuing as the blockchain company’s chief executive.
- Blackshear plans to remain an adviser to Mysten Labs and developers across the Sui ecosystem.
- Move’s creator said a foundation is being developed and he intends to remain involved afterward.
- Anthropic is expanding defensive cyber research as frontier models improve software vulnerability discovery capabilities rapidly.
Blackshear announced the move in posts on X, saying the role would let him return to hands on technical work while studying a new problem area. He did not disclose his starting date, reporting line or specific projects at Anthropic.
Blackshear said he was motivated by a period in which the “balance of power between attackers and defenders is shifting.” The comment is his assessment, not a measured industry result. However, Anthropic’s recent research supports the broader concern. The company said Claude Opus 4.6 could identify high severity software vulnerabilities at scale, while its Frontier Red Team studies how advanced models could strengthen defense and offensive activity.
Blackshear will remain involved with Mysten and Sui
Blackshear said he would remain a close adviser to Mysten Labs and respond to Sui ecosystem builders who seek his help. Mysten’s leadership page identified him as a cofounder and CTO before the announcement, alongside cofounder and chief executive Evan Cheng. Blackshear said Cheng will now set the company’s technical vision, although Mysten had not published a separate succession statement.
The departing executive credited Cheng with recruiting many of Mysten’s strongest technical employees and noted his previous leadership experience at Apple and Meta. Blackshear also thanked Mysten Labs staff and the wider Sui community. His advisory role may provide continuity, but the company has not disclosed whether it will appoint another CTO or redistribute his duties.
Mysten was founded by former Meta engineers and became the original contributor to the Sui layer one blockchain.
Mysten Labs partnered with Google Cloud to use generative AI in code development and auditing. The collaboration included tools trained on Move and an AI based auditing system designed to identify vulnerabilities in Move, Rust, TypeScript and Solidity code. That work placed artificial intelligence and blockchain security within Mysten’s strategy before Blackshear joined Anthropic.
Move Foundation plans remain at an early stage
Blackshear created Move while working at Meta and has spent more than eight years developing the language. Sui Foundation materials describe Move as a smart contract language designed around ownership, scarcity and safer handling of digital assets. Its resource model aims to prevent certain programming errors, while Sui’s version adds an object centered structure and programmable transaction blocks.
Blackshear said a Move Foundation is “in the works” and that he hopes to remain involved. The statement is forward looking. He did not provide a launch date, governance structure, leadership team or funding plan. It is also unclear whether the proposed foundation would oversee the language across several blockchains or focus on narrower technical standards.
A separate foundation could provide a neutral forum for language development, documentation and governance. Still, no official organization or timetable accompanied Blackshear’s departure, so its eventual scope remains uncertain.
In related coverage, the $260 million Cetus Protocol exploit showed that a secure programming language cannot remove every application level risk. Researchers said the affected contracts executed permitted instructions, while the failure involved pricing and liquidity controls above the language layer. The incident showed why smart contract safety also depends on protocol design, monitoring and operational response.
Anthropic is expanding defensive security research
Blackshear joins Anthropic as the company increases research into AI enabled cyber threats. Anthropic reported in June that it studied 832 accounts linked to malicious activity and mapped their behavior across the MITRE ATT&CK framework. It said it banned those accounts and found AI assistance across reconnaissance, malware development, evasion and other attack stages.
Anthropic is also testing defensive uses of its models. Project Glasswing brought together about 50 partners to search critical software for vulnerabilities, while separate work with Pacific Northwest National Laboratory used Claude in simulated attacks on a water treatment system. These company reported results do not prove defenders will consistently stay ahead, but they show the research field Blackshear is entering.
Blackshear’s background in programming languages, static analysis and automated bug finding fits that work. Before Mysten, he worked on Move and related security tools at Meta. Sui’s official archive identifies him as Move’s creator and a former principal engineer at the company.
What happens next depends on announcements from Anthropic and Mysten Labs. Anthropic has not detailed Blackshear’s team or research agenda. Mysten has not confirmed a replacement CTO. Developers will also watch whether the proposed Move Foundation receives formal leadership, funding and a launch schedule.
