Proof of Humanity

• Name: Proof of Humanity
• URL: https://proofofhumanity.id/
• Category: proof-of-personhood registry / challenge-and-arbitration human registry / sybil-resistance governance primitive
• Tags: ethereum-ecosystem
• Summary: Proof of Humanity is a challengeable human registry. The signup flow is not the point. The machinery that matters is vouching, challenge rights, evidence rules, and Kleros arbitration. The v2 design matters because Humanity IDs travel better than the old one-wallet check without dropping the one-human-one-registry logic.
• What it does:
  • Lets users submit a human profile with identifying media and social verification so they can be admitted to a sybil-resistant human registry
  • Uses vouching, pending requests, and registry state transitions to determine whether an applicant or existing registrant remains accepted
  • Exposes onchain registry contracts so integrators can query whether an address is human or retrieve the bound humanity identifier
  • In v2, introduces a non-transferable Humanity ID that links a human to a persistent identifier rather than only to one wallet address
  • Supports cross-chain deployments and tells integrators to read state through CrossChainProofOfHumanity rather than chain-local registries
  • Makes the registry usable for one-person-one-vote governance, anti-sybil funding, universal-basic-income-style distributions, and other systems that need a challengeable list of humans
• Key claims:
  • PoH is a sybil-resistant registry, not a broad identity stack. The point is to keep a challengeable list of humans under adversarial conditions.
  • The reusable mechanism is the challenge process. Membership is stabilized by policy, evidence handling, and Kleros arbitration rather than by one enrollment check.
  • The v2 shift from wallet status to Humanity ID is the main upgrade. It gives apps a cleaner query surface for recovery, continuity, and cross-chain use.
  • The cross-chain proxy design makes the middleware ambition plain. Integrators are supposed to query a portable human-status layer, not babysit every local registry.
  • The hard parts are still governance edge cases: identity theft, profile farming, privacy tradeoffs, and recovery without breaking the one-human-one-ID rule.
• Whitepaper: No standalone PoH-native whitepaper PDF surfaced as the clearest current canonical reference in this pass. The strongest primary materials reviewed here were the official PoH/Kleros docs plus the v1 and v2 contract repositories and governance materials; see ../whitepapers/proof-of-humanity-primary-sources-2026-05-10.md.
• Sources:
  • https://proofofhumanity.id/
  • https://docs.kleros.io/products/proof-of-humanity
  • https://github.com/Proof-Of-Humanity/Proof-Of-Humanity
  • https://raw.githubusercontent.com/Proof-Of-Humanity/Proof-Of-Humanity/master/README.md
  • https://github.com/Proof-Of-Humanity/proof-of-humanity-v2-contracts
  • https://raw.githubusercontent.com/Proof-Of-Humanity/proof-of-humanity-v2-contracts/master/README.md
  • https://raw.githubusercontent.com/Proof-Of-Humanity/proof-of-humanity-v2-contracts/master/contracts/interfaces/IProofOfHumanity.sol
  • https://gov.proofofhumanity.id/
  • https://gov.proofofhumanity.id/t/the-way-forward-for-proof-of-humanity-origin/2861

Internal linkages

• Best read beside world-id, human-passport, and kleros.

Control surface

• The leverage sits in vouching rules, challenge rights, evidence thresholds, arbitrator design, recovery policy, and upgrade control over the registry and query layer.

• Treat Proof of Humanity as dispute-governed registry infrastructure, not as generic identity middleware.

• Last reviewed: 2026-06-18 UTC