Identity programmes often begin with a database, a credential or an application. The durable design question is broader: which institution is authoritative for each decision, and how does that authority travel through the system?
An identity exchange has several actors
Registration establishes or updates a record under a mandate. An issuer makes a claim in a credential. A wallet protects credentials and keys for a holder. A relying party asks for information to support a service decision. A verifier checks the evidence it receives. A trust authority defines which issuers or verifiers are accepted for a particular purpose.
These roles can be performed by the same organisation in some ecosystems, but they are not the same function. Architecture should document the authority and accountability of each role rather than infer them from a certificate, a network connection or a product label.
Keep trust decisions in their own domains
An issuer certificate can help a verifier establish who signed a credential and whether its data was altered. It does not, by itself, authorise every relying party to request that credential. Likewise, the trust list for passport document signers should not automatically authorise digital identity verifiers. Each trust relationship needs a defined purpose, source, update process and revocation policy.
Protocols can support these decisions without choosing a universal trust framework. OpenID for Verifiable Presentations describes signed requests and trust frameworks, while the ecosystem must still establish which authorities and profiles apply.
Design for operational ownership
For every trust decision, the architecture should answer:
- Who is authorised to make the decision?
- Which signed or otherwise authenticated source carries that authority?
- How are updates, expiry and revocation handled?
- What happens when the source is stale or unavailable?
- Which evidence can an auditor reproduce later?
The result is more than a clean diagram. It is a system where authority, cryptographic evidence and operational responsibility align.