Sam Blackshear, the programmer who created the Move smart-contract language and co-founded Mysten Labs, is leaving the company to join Anthropic, where he will focus on defensive security research. Blackshear co-founded Mysten Labs — the studio behind the Sui blockchain — in September 2021 alongside four former Meta colleagues, building on work the group had started on Move while at Meta's Diem project.
Blackshear isn't cutting ties with the ecosystem entirely. He will stay on as an adviser to Mysten Labs, to Sui builders more broadly, and to the planned Move Foundation, while Evan Cheng — who continues as Mysten's chief executive — takes over the company's technical vision in Blackshear's place.
Why he's moving toward AI security specifically
Blackshear has framed the move as a chance to work on security research at a moment when the balance between attackers and defenders is shifting fast, driven by how quickly frontier AI models are improving at discovering software vulnerabilities. Anthropic has been expanding its defensive cyber-research efforts to match that pace, positioning the move as less a departure from blockchain work than a shift toward the layer underneath it — the software-security problem that affects every system, crypto or otherwise, as AI-assisted vulnerability discovery becomes more capable.
Related: German Lightning Developer Admits Security Fears Kept Him Out of Bitcoin
What it means for Move and Sui
Move was designed from the ground up with resource-oriented safety guarantees meant to prevent the kind of asset-duplication and reentrancy bugs that have plagued other smart-contract languages, and it now underpins both Sui and Aptos. Blackshear's departure from day-to-day Mysten Labs operations doesn't threaten that design directly, but losing the language's original architect from an active leadership role is a meaningful transition for an ecosystem still working to expand Move's adoption beyond its two flagship chains.
A broader pattern
Blackshear's move adds to a small but notable trend of senior blockchain technologists shifting into AI safety and security work as frontier labs compete for talent capable of reasoning about adversarial systems at a deep technical level. For Mysten Labs, the succession plan — an advisory role for Blackshear paired with Cheng absorbing the technical vision — suggests the company is treating this as a managed transition rather than a disruptive exit, though how Sui's roadmap evolves without its co-founder in an operational seat will only become clear over the following months.
