Prove who you are. Reveal nothing else.

Decentralized identity — also called self-sovereign identity, or a reusable ID — gives a person full control over their own identity and data, without relying on a central authority. It starts with a decentralized identifier (DID): a globally unique identifier cryptographically bound to a key the holder controls.

A verifiable credential is a cryptographically signed statement an issuer makes about a holder — a passport authority asserting a nationality, a university a degree, an employer a role. The holder keeps it in a wallet and presents it to a verifier, who confirms the credential's integrity and authenticity by checking the issuer's and the wallet's signatures in the presentation — without ever contacting the original issuer. That offline check is what preserves the holder's privacy.

The credential carries two privacy options. Selective disclosure shares only the exact attributes a transaction needs. Zero-knowledge proofs go one step further — prove a property of a credential, over 18 or resident in the EU, without revealing the claim behind it. The verifier learns one bit, not the birthday.

Partisia ships the issuer side too: a credential-issuance service that authenticates the holder over OAuth2 and delivers the credential to their wallet over the OpenID for Verifiable Credential Issuance (OID4VCI) protocol — so any organisation can become a verified issuer.