Sam Blackshear, co-founder and chief technology officer of Mysten Labs, is departing the company to join AI firm Anthropic, where he will focus on defensive security research. The leadership change comes as AI-driven threats increasingly target blockchain and cryptocurrency ecosystems, making advanced cybersecurity a growing priority across the industry.

Move to Anthropic

Anthropic, best known for developing the Claude family of large language models, has established itself as one of the most prominent AI safety companies. Blackshear's recruitment signals the firm's growing investment in defensive security as AI systems become both more capable and more widely deployed across critical infrastructure.

Blackshear stated that his new role at Anthropic will center on defensive security research, an area he described as growing in importance as attackers increasingly leverage AI-powered tools. He noted that adversaries are becoming more sophisticated, using AI to package and scale their attacks, which makes more advanced defensive research a necessity.

He described the move as taking on a challenge that brings him the greatest enjoyment: solving difficult technical problems in emerging technology spaces.

I am leaving Mysten Labs and joining Anthropic to work on defensive security research.

— Sam Blackshear (@b1ackd0g) August 5, 2026

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Continued Involvement with Mysten Labs and Sui

Blackshear confirmed that he will remain a close advisor to Mysten Labs and continue supporting Sui builders. He also expressed ongoing dedication to the Move programming language, which he has worked on for over eight years. The planned Move Foundation, he said, will support the future governance and adoption of the language.

Move was originally developed at Meta for the Diem blockchain project before Mysten Labs adapted and extended it for Sui. Its resource-oriented programming model is intended to reduce common vulnerabilities in smart contracts and improve asset safety, an approach that has influenced broader conversations about secure-by-design smart contract development across the Layer 1 landscape.

Blackshear praised Mysten Labs' engineering team, describing it as the best technical team he has worked with in his career.

Leadership Transition

Company co-founder and CEO Evan Cheng will now spearhead the long-term technical direction of Mysten Labs and the Sui project. Mysten Labs stated that its roadmap remains unchanged following Blackshear's departure.

Blackshear expressed confidence in the transition, crediting the company's ability to attract top engineering talent from companies including Apple and Meta.

AI Security as a Blockchain Priority

Blackshear's move comes at a time when an increasing number of blockchain developers face AI-driven cyber attacks. Security researchers have noted that AI can be used to identify vulnerabilities, create exploits, enhance phishing methods, and compress the attack cycle in decentralized network environments. The crypto sector has lost tens of billions of dollars to hacks and exploits over recent years, underscoring the stakes of improving both code-level security and operational defenses.

At the same time, AI is playing a growing role as a defensive tool. Companies are investing in automated threat detection, vulnerability analysis, and security monitoring systems that can operate faster than manual, human-led processes. Anthropic's own research into model behavior, red-teaming, and misuse prevention places Blackshear's new work at an intersection of AI capability and security that few organizations are positioned to explore.

With Blackshear remaining affiliated with the project and the Move Foundation moving forward, the Sui ecosystem is positioned for continuity, while one of its founding architects embarks on a new chapter in AI-powered cybersecurity.