Iden3 / Privado ID
Identity ProtocolsZero-knowledge proof identity protocol providing zkSNARK-based identity verification without revealing personal data. Created Circom (the leading ZK circuit compiler used by Polygon Hermez, Dark Forest, Tornado Cash). Powers Privado ID (formerly Polygon ID), enabling private-by-default on-chain identity verification with permissionless attestation across multiple EVM chains. Merged with Disco.xyz in September 2024 to build Unified Identity across blockchains and legacy systems.
Hybrid Community Medium capture risk
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Details
License GPL-3.0 / Apache 2.0 / Permissive
Dev Status Released
Owner 0KIMS Association (open-source protocol); Privado ID (formerly Polygon ID) as commercial implementation; Jordi Baylina (Polygon co-founder) as advisor; David Z (Privado ID CEO); merged with Disco.xyz (Evin McMullen, now CSO)
Country Spain
Start Year 2018
Stack Golang, JavaScript/TypeScript, Solidity, Circom
Funding VC
Last Investigated Jan 15, 2026
Identity Protocol Attributes
Permissions Mixed — GPL-3.0 and Apache-2.0 across components. The Iden3 smart contracts (iden3/contracts) and Circom ZK compiler are published under GPL-3.0 by the 0KIMS Association. The circom_runtime library is published under Apache-2.0. Privado ID's issuer-node and wallet SDK follow the same mixed pattern. GPL-3.0 components require derivative works to be open-sourced under the same terms. Commercial use is permitted under both licenses.
Authentication & Identity Decentralized ID (DID) with ZK-native authentication; iden3 communication protocol for ZK-based auth requests/responses; no personal data shared during verification
Storage Model Blockchain/Ledger (identity states as Merkle tree roots on-chain; credential claims stored in user identity trees; state transitions published to smart contracts across multiple chains)
Interoperability High: multi-chain EVM support (Ethereum, Polygon, Privado, Linea, zkEVM, Arbitrum, Base, Optimism post-Disco merger); Disco merger adds cross-chain credential portability; W3C VC compatible
Data Portability Standards-based export (W3C Verifiable Credentials; portable across any iden3-compatible verifier; multi-chain state resolution)
Governance & Decision Making Foundation-governed (0KIMS Association for open-source protocol; Privado ID as commercial entity; community governance for protocol evolution)
Protocol Maturity / Standardization Community Standard (published did:iden3 method specification; Circom circuit specifications; iden3 protocol docs; 0KIMS Association governed)
Identity Standards W3C DID; W3C Verifiable Credentials; Iden3 communication protocol; JSON Web Zero-knowledge (JWZ); Groth16 ZK proofs
DID Methods Supported did:iden3, did:polygonid (both supported; method-specific identifiers include blockchain and network IDs; base58-encoded deterministic identifiers from Genesis ID)
Key Management User-controlled (mobile wallet with on-device key storage; identity trees managed locally; state published on-chain)
Credential Types Verifiable Credentials (W3C VCDM); KYC credentials; age verification; proof of humanity; membership proofs; custom schema-based credentials
Verification Method Zero-knowledge proofs (Groth16 zkSNARKs — verifier receives only proof, never underlying data; on-chain state verification via smart contracts; atomic query circuits for credential attribute verification)
Privacy Features Zero-knowledge proofs (core design principle — verifier learns nothing beyond the proof result); selective disclosure via ZK circuits; unlinkable presentations; no personal data stored on-chain
Authentication Methods ZK proof-based challenge-response (JWZ authentication); QR code scanning; deep linking for mobile wallet
Revocation Mechanism On-chain state management (identity state transitions invalidate previous states; revocation via Merkle tree updates; issuer-controlled revocation reflected in on-chain state roots)
Agent Types Supported Humans (individuals); Organizations (issuers/verifiers); DAOs/Collectives (on-chain governance integration); Pseudonymous entities
Wallet/Client Types Mobile app (Privado ID wallet for iOS/Android); SDK/Library integration (Go, JS, mobile SDKs); web-based verification
Recovery Mechanisms Seed phrase backup (wallet-level recovery); identity recovery via Genesis ID (deterministic identity from initial key material)
Compliance / Regulations GDPR compliant (ZK proofs enable data minimization by design); eIDAS alignment (Telefónica Tech EU partnership); KYC/AML support via credential schemas
Credential Exchange Protocols Iden3 communication protocol (custom authorization request/response with ZK proofs); OIDC4VC (planned via Disco merger integration); Presentation Exchange
Trust Framework Blockchain consensus (on-chain state verification via GIST — Global Identity State Tree); cryptographic verification (ZK proofs); trusted issuer registries (OCI-style for pharma/enterprise)
Cost Model Free (no gas fees for ZK proof generation; gas fees for on-chain state transitions; Privado mainnet available)
Censorship Resistance High (ZK proofs are user-generated and verifiable without central authority; multi-chain deployment; identity state anchored on public blockchains)