Does a valid signature mean a credential is still usable?

A workshop credential may be suspended before it expires. Its signature can still verify: it protects the credential data, without automatically answering whether entry is permitted now.

Verifiable credentials (VCs) can state when they become valid and when they expire, and can provide status information such as suspension or revocation. An absent expiry does not remove applicable status or business checks.

A status type defines how its information is interpreted and obtained; the data model does not require one mechanism for every credential. Services also decide acceptable freshness and how to handle unavailable status information. These rules explain why a request succeeds or fails.

Does suspension rewrite the credential?

Suppose an equipment qualification is temporarily suspended. The issued file can remain unchanged while a verifier checks status before permitting an operation. Suspension commonly allows a later return to use; revocation invalidates a credential. The chosen status mechanism defines the precise semantics.

Status checks also have privacy costs. Asking an issuer about an individual credential on every use may reveal a usage trail. Examine who can observe requests and how long status information is cached. A verifier needs an explicit policy for unavailable status information: refuse, defer or use another review process.

Sources and further reading

Book and sources

This lesson develops the questions in Chapter 4 of 《区块链实战》 with later standards. It is not an excerpt.