Ethereum co-founder Vitalik Buterin has voiced concerns about the privacy implications of World, the digital identity initiative spearheaded by Sam Altman and Alex Blania under their company Tools for Humanity. Formerly known as Worldcoin, the project seeks to verify human identity through biometric iris scans, creating a blockchain-based ID system that can differentiate humans from AI.
While Buterin acknowledged that World’s use of zero-knowledge (ZK) proofs to protect user anonymity is promising, and aligns with broader efforts in digital passport and ID technology, he warned that the core concept still poses serious privacy risks. Even with ZK protections in place, the model effectively enforces a “one-person, one-ID” structure.
“Pseudonymity in the real world often requires multiple accounts,” Buterin explained. “If everyone is tied to a single digital identity, even anonymously, it becomes harder to shield personal activity from unwanted scrutiny.”
He cited real-world examples to illustrate the risk, such as the U.S. government requiring visa applicants to make their social media profiles public for ideological screening. Even if identities aren’t publicly linked, governments could compel individuals to reveal their private keys, granting access to their entire digital history.
To address these issues, Buterin proposed an alternative: a pluralistic identity system. Rather than relying on a single, dominant authority, like a government or platform, pluralistic systems are decentralized and can be based on multiple, overlapping sources of identity. These systems can function either explicitly (through peer verification from trusted individuals) or implicitly (by aggregating credibility across various platforms and methods).
In conclusion, Buterin suggested that existing one-per-person identity models like World should evolve by merging with social-graph-based identity solutions, which use a network of social connections to establish trust without sacrificing anonymity. In his view, this hybrid approach offers the most realistic path forward for preserving privacy in a digitally verified world.
