Sam Blackshear (샘 블랙시어), co-founder and former chief technology officer of Sui blockchain developer Mysten Labs, is leaving the company to join Anthropic.

Cointelegraph reported on Aug. 6 that Blackshear said he is stepping down to take on defensive security research.

The move is drawing attention because a key technical figure in the Sui ecosystem is shifting into AI security. Blackshear said Evan Cheng (에번 청), Mysten Labs co-founder and chief executive officer, will take charge of the company’s technology vision going forward.

Blackshear cited hands-on technical research and new problem areas as the reasons for his decision. "When I look back on my career, I was happiest when I explored new problem areas while doing technical work myself," he said. "This opportunity is a role where I can do both." He also stressed that the spread of AI is changing the security landscape. "I became motivated to work in security at a time when the balance of power between attackers and defenders is shifting," he said.

The move comes as AI is increasingly used to find software vulnerabilities, automate phishing attacks and speed up attacks on blockchain infrastructure. Mysten Labs' top technology executive is moving away from crypto infrastructure development and into AI-based defensive security research for related reasons.

Blackshear said he does not intend to completely disengage from Mysten Labs and the Sui ecosystem. He said he wants to remain a close adviser to Mysten Labs and continue to be involved in the Sui ecosystem and Move Foundation activities.

Mysten Labs was founded in September 2021 by Blackshear and four former Meta executives, among others. The company is known as the developer behind the Sui blockchain. With the leadership change, Mysten Labs will reorganise its management and technology leadership around Cheng.

In this situation, market attention is expected to split in two. One is how Mysten Labs and the Sui ecosystem will set their development direction after Cheng takes charge of the technology vision. The other is what impact the defensive security research Blackshear will take on at Anthropic could have on security competition surrounding AI and blockchain infrastructure.