Ethereum co-founder has raised four primary concerns of Worldcoin: privacy, accessibility, centralization, and security.
While Worldcoin's Proof-of-Personhood (PoP) system is designed to authenticate unique users without revealing personal data, Buterin warns that any data leak could lead to misuse of identity information. He also points out that accessibility is an issue, as participation requires physical access to a device called "Orb," potentially limiting the project's reach. Lastly, he mentions security risks such as phone hacking and coercion to scan irises.
Despite these concerns, Buterin does see the value in the concept of Worldcoin, and suggests a combination of social-graph-based, general-hardware biometric, and specialized-hardware biometric techniques as a potential solution.
