Introduction to Trust Chains
A Trust Chain is a hierarchy of accredited organisations that gives meaning and legal weight to Verifiable Credentials issued on EBSI. Rather than trusting any credential that claims to come from a given issuer, a verifier can follow the chain of accreditations all the way up to a root authority — establishing who authorised this issuer, and on what basis.
Roles in a Trust Chain
| Role | Full name | Responsibility |
|---|---|---|
| RTAO | Root Trusted Accreditation Organisation | The anchor of the trust chain. Accredited directly by EBSI; can accredit TAOs and TIs within a domain. |
| TAO | Trusted Accreditation Organisation | Accredited by the RTAO or another TAO; can accredit Trusted Issuers within their sector. |
| TI | Trusted Issuer | Accredited by a TAO; issues domain-specific Verifiable Credentials to holders. |
| Holder | — | Receives credentials from TIs and presents them to verifiers. |
How accreditation flows
Each accreditation is itself a Verifiable Credential stored on the EBSI Trusted Issuers Registry (TIR), making the entire chain auditable and tamper-evident.
Before you start
Before onboarding into a trust chain you should:
- Design your Trust Chain — identify the domain, roles, and JSON schemas you will use. See Design your Trust Chain.
- Choose your role — each role has a distinct onboarding process. Start with the guide that matches your organisation.
- Set up a wallet — every participant needs an Organisation Wallet with the appropriate capabilities for their role.