World Opens ProveKit to Developers, Letting Phones Prove Age Without Sharing IDs - Unchained

World said Wednesday that ProveKit, the zero-knowledge proving toolkit already running inside its World ID identity checks, is open to outside developers to build on, letting a phone confirm a fact about its owner without transmitting the document that proves it.

The design points at a specific failure. Verifying an age or a nationality online usually means uploading a photo of a passport or a driver’s license to a company that then stores it, which turns every verification vendor into somewhere worth breaking into. Security journalist Brian Krebs reported Tuesday that a dark web service called Nexus is selling scans of more than 153 million US and Canadian driver’s licenses, apparently taken from a breached identity-verification vendor, and that the FBI’s New Orleans field office has opened an investigation.

How the proofs work

Proofs are generated on a person’s own phone or browser, according to World, and whoever is checking receives only confirmation of the specific claim, “without revealing the underlying personal data.” World said in its announcement that it built the toolkit around local proof generation rather than the delegated kind, where a server does the computation and therefore sees the inputs, “reducing the risk of data exposure and keeping individuals in control of their personal information.”

Per World, ProveKit targets 128-bit post-quantum security, needs no trusted setup, uses the WHIR hash-based commitment scheme, and has been independently audited by Least Authority. It supports Noir, the Rust-inspired language Aztec built for writing zero-knowledge circuits. World’s published benchmarks put proving time at two to three seconds on an iPhone SE 3 and under 30 seconds on a low-end Android handset.

The code predates the announcement

The repository is not new. worldfnd/ProveKit has been public on GitHub since November 2024, and has carried an MIT license and a tagged v1.0.0 release since May. The only release dated Wednesday, v1.0.1, upgrades the bundled Noir toolchain and aligns crate versions.

World, co-founded by OpenAI CEO Sam Altman, raised $52.5 million in July with every token locked up for a year, and in March shipped a toolkit with Coinbase for AI agents backed by a verified human. World said ProveKit v2 is in development, aimed at cutting proof size, proving time and memory use, and at adding more efficient on-chain verification.

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