Buterin: Zero-Knowledge Digital IDs Still Carry Coercion, Privacy Risks

Ethereum co-founder Vitalik Buterin has raised concerns that digital identity systems using zero-knowledge proofs, such as Sam Altman’s World project, could weaken online pseudonymity while introducing new risks.

Buterin Argues One-ID-Per-Person Systems Create New Vulnerabilities

In a June 28 blog post, Buterin argued that even privacy-focused designs face fundamental challenges when enforcing a one-identity-per-person rule. The Ethereum co-founder acknowledged that zero-knowledge technology improves upon traditional ID systems by verifying credentials without revealing personal data.

He noted that projects like Sam Altman’s Worldcoin (now simply referred to as World), Taiwan’s digital ID program, and upcoming European Union (EU) frameworks use this method to authenticate users while combating bots and fraud. However, he warned that strict single-identity systems undermine practical pseudonymity. Users often rely on multiple accounts—such as public profiles and anonymous aliases—to compartmentalize online activity.

A universal ID could collapse these distinctions, forcing all interactions under one verifiable identity. A second major concern he shared is coercion. Governments, employers, or platforms could pressure users to disclose their primary identity key, linking previously separate accounts. While technical safeguards exist, Buterin noted they cannot fully eliminate this risk in centralized or government-mandated systems.

He also highlighted unresolved edge cases, such as stateless individuals, biometric errors, or document accessibility gaps—problems that disproportionately affect one-ID systems. Wealth-based anti-sybil mechanisms, he added, fail to address needs like equitable governance or universal basic services.

“There is also another way to accomplish a similar thing: ‘universal basic services.’ Give each person with an identity the ability to send a limited number of free transactions within a particular application,” Buterin wrote on Saturday.

He added:

This approach is potentially more incentive-aligned and capital-efficient, because it can be done by each application that benefits from such adoption, without needing to pay for non-users, though this comes with the tradeoff of being less universal (users only get guaranteed access to participating applications).

Instead, Buterin advocated for “pluralistic identity” models with no single dominant issuer. These could be social-graph-based or rely on competing providers, making coercion harder and preserving pseudonymity. He cautioned that any ID system approaching universal adoption risks recreating the flaws of one-identity regimes.

Buterin’s analysis comes as Worldcoin surpasses 10 million users and governments accelerate digital ID rollouts, intensifying debates over privacy and scalability in online authentication.