Mysten Labs CTO Leaves for Anthropic AI Security Role

Mysten Labs was founded in 2021 by veterans of Meta Platforms’ Diem blockchain project and develops Sui, a Layer 1 network built around the Move smart-contract language created by Sam Blackshear. The company raised $300 million in a September 2022 Series B round that valued it at more than $2 billion. His departure matters because it shifts a prominent blockchain architect toward the increasingly competitive field of AI security.

Blackshear said on Aug. 5, 2026, that he was leaving Mysten Labs, where he was co-founder and chief technology officer, to join Claude maker Anthropic and work on defensive security research. He said AI is changing the balance between attackers and defenders, motivating him to investigate how defenses can keep pace with fast-moving threats. The announcement did not disclose his start date, compensation or a successor at Mysten Labs.