Beginner Guide
What Is Proof of Personhood? A Beginner's Guide
How verified-human credentials work, why they matter as AI floods the open internet, and the tradeoffs between biometrics, social graphs, KYC, and zero-knowledge identity.
The Directory
The other half of the property: a curated directory of decentralized identity and proof-of-personhood protocols. Categorized, filterable, with honest notes on privacy tradeoffs and jurisdictional restrictions.
Biometric Protocols
Verify humanness via unique physical characteristics — iris, palm, face. Privacy tradeoffs are real and worth understanding before participating.
World (Worldcoin)
Iris-scanning Orb generates a unique World ID proving you're a unique human. Largest deployed biometric proof-of-personhood network. Token: WLD.
Humanity Protocol
Palm-scanning approach to proof-of-personhood. Less invasive than iris scanning. Newer ecosystem, still expanding verifier coverage.
iProov
Face liveness detection used by governments and banks. B2B/B2G focus rather than crypto-native, but a foundational biometric vendor.
Onfido
Document plus face verification. Widely used by fintechs and exchanges for KYC. Acquired by Entrust in 2024. Traditional but reliable.
Social Proof / Web of Trust
Verify humanness through social vouching, video calls, or community attestation. No biometrics required.
BrightID
Web-of-trust identity built on video-call verification ceremonies. Used by several DAOs for fair voting. Strong on privacy, weaker on scale.
Proof of Humanity
Ethereum-based registry where users submit a video and existing humans vouch for them. Pays a small UBI in UBI tokens. Real but small community.
Zero-Knowledge Identity
Prove attributes about yourself (citizenship, age, credentials) without revealing the underlying data. The most privacy-preserving track.
Sismo
zkBadges and zk-Connect — prove credentials and group memberships without revealing wallet addresses or personal data. Strong builder community.
Privado ID
Zero-knowledge identity stack — issue, hold, and verify credentials without exposing underlying data. Formerly Polygon ID. Designed for institutional use.
zkPass
Prove facts from any existing web2 data source (bank account, university transcript, employment record) using zkTLS. No biometrics, no new accounts.
Reclaim Protocol
Similar to zkPass — use zkTLS to import and prove web2 data on-chain without exposing the source data. Active developer ecosystem.
Holonym Hub
Zero-knowledge identity verification — prove citizenship, age, or unique humanity without exposing the underlying documents. Multiple use cases.
KYC Crypto Identity
Traditional KYC-style identity verification adapted for wallet- and chain-native use cases.
Civic
Identity verification tied to Web3 wallets. Used by some DeFi platforms and chains for compliant access. Token: CVC.
Veriff
Document-plus-selfie identity verification platform. Widely used by exchanges and fintechs. B2B SaaS rather than crypto-native.
Multi-Source Aggregators
Build a humanity score by combining many smaller signals — accounts, credentials, on-chain history, attested stamps.
Gitcoin Passport
The dominant multi-source aggregator. Stack "stamps" from GitHub, Google, Discord, ENS, Coinbase, and others to build a humanity score used by airdrops, grants, and DAOs.
Coinbase Verifications
Coinbase-issued on-chain attestations confirming your wallet is tied to a verified Coinbase account. Lightweight humanity signal used by Base ecosystem apps.
Mining / Work-Based Proof
Prove humanness by completing periodic tasks AI struggles with. Niche but conceptually elegant.
Idena
Periodic synchronous "validation ceremonies" where humans solve puzzle flips AI can't easily handle. Earn iDNA tokens for participating. Small but committed community.
Builder Tools
SDKs, scoring services, and infrastructure for developers who need to consume or aggregate humanity signals.
Trusta Labs
Sybil-resistance scoring for Web3 — analyzes wallets for bot-like behavior and assigns a humanity probability. Used by airdrops and protocols for fair distribution.
Nomis Score
On-chain reputation scoring across multiple EVM chains. Useful as a humanity / behavior signal for protocols evaluating users.
Privy
Wallet authentication layer that ties social logins to embedded wallets. Common substrate for apps that want a humanity layer without users managing seed phrases.
Web3Auth
Social-login + MPC wallet recovery. Similar to Privy in spirit — let humans onboard without giving up account portability. Multi-chain.
Real-World Use Cases
Apps actively consuming proof-of-personhood credentials. Helpful to see how the credentials are actually being used.
World App Ecosystem
Mini-apps inside World App that require verified humanity — payments, polls, games, identity-gated access. The largest live deployment of "verified-human only" apps.
Gitcoin Grants
Quadratic funding rounds for public goods — uses Gitcoin Passport scores to weight contributions toward verified humans. A practical, working sybil-resistance use case.
Submit a project we missed
Building a proof-of-personhood protocol, sybil-resistance tool, or app that consumes verified humanity? Get listed. Use the contact link below.