Default _sd_alg of sha-256 when not present at the top level

RFC 9901 §4.1.1MUSTRoles: issuer, holder, verifier

Requirement as recorded in the ProtocolSoup registry

If the _sd_alg claim is not present at the top level, a default value of sha-256 MUST be used.

Read §4.1.1 in RFC 9901

Self-test verdict

PassCommit 97df6a8Evaluated 2026-10-11

This is ProtocolSoup's result against its own implementation at the commit shown. It is not a certification of ProtocolSoup or of any other product.

Tests

TestSDJWTDisclosureDigestsExtractsNestedCommitments
./internal/vc
Pass
TestSDJWTDisclosureDigestsRejectsUnsupportedAlgorithm
./internal/vc
Pass

Implementation

backend/internal/vc/sdjwt.go

Related requirements

SDJWT-001Same digest value not appearing more than once in the SD-JWT SDJWT-003Claim names _sd and ... cause SD-JWT rejection

All RFC 9901 requirements · OID4VCI protocol page