Google open-sourced zero-knowledge age verification

Google published a zero-knowledge proof library for age verification that runs in the browser. The library compiles to WebAssembly, which means it does not need server round-trips to verify someone is old enough to see restricted content. Zero-knowledge proofs are cryptographic systems that let you prove a statement is true without revealing the underlying data. In this case, the statement is “I am over 18” and the data is your actual birth date. The verifier learns only the boolean, not the timestamp. The interesting bit is Google releasing this as open infrastructure instead of a product. Most age-gate implementations today are terrible: third-party cookies that track you across sites, government ID uploads to sketchy vendors, or honour-system dropdowns that everyone lies on. A client-side ZKP that does not leak your birth date or browsing history solves the privacy problem, but only if every site can actually deploy it. WebAssembly is the right target. JavaScript crypto libraries are fast enough for symmetric operations but ZKP verification involves elliptic curve math that tanks performance without native speed. WASM gets you within striking distance of native C without asking developers to rewrite their stacks. The repo includes reference implementations and benchmarks. Verification takes around 50 milliseconds on a modern laptop. That is fast enough to inline into page load without users noticing lag. One caveat: this only works if the age claim is anchored to a trusted attestation, like a government-issued credential. The ZKP proves the attestation is valid and current without revealing what it says, but someone still has to issue the credential in the first place. Google punts on that step, which is the politically harder half of the problem.

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Source: Opening up ‘Zero-Knowledge Proof’ technology to promote privacy in age assurance