Protocol Flow

The issuance protocol separates issuer-visible credential information from the holder-hidden value that is blinded during signing.

Issuance

sequenceDiagram
  participant I as Issuer
  participant H as Holder

  I->>I: Generate issuer keys
  I->>H: Share signed IssuerAuthority
  H->>H: Choose blind_msg and credential info
  H->>H: Create IssuanceRequest and PendingIssuance
  H->>I: Send IssuanceRequest
  I->>I: Bind visible info and blind-sign request
  I->>H: Send IssuanceResponse
  H->>H: Finalize response into SignedCredential
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Verification

sequenceDiagram
  participant V as Verifier
  participant I as Issuer
  participant H as Holder

  I->>V: Share trusted IssuerAuthority
  H->>V: Present SignedCredential
  V->>V: Verify issuer is trusted
  V->>V: Verify credential signature
  V->>V: Check ingested revocations
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Holder Authorization

sequenceDiagram
  participant W as Holder Wallet
  participant A as External App
  participant V as Verifier

  A->>W: Share subject_pubkey
  W->>W: Select SignedCredential
  W->>W: Sign HolderAuthorization
  W->>A: Send HolderAuthorization
  A->>V: Present SignedCredential and HolderAuthorization
  V->>V: Verify credential and holder authorization
  V->>V: Apply subject_pubkey and credential policy
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The SDK signs holder authorizations with the holder identity key and derives the credential digest from the selected SignedCredential. The verifier-side SDK check verifies the credential, holder authorization signature, holder binding, authorized credential digest, and authorization issued-at time. Subject-key proof-of-possession, credential schema policy, storage, and transport stay in the application.

Revocation

sequenceDiagram
  participant I as Issuer
  participant V as Verifier

  I->>I: Compute credential digest
  I->>I: Sign SignedRevocation
  I->>V: Publish or transport revocation
  V->>V: Verify revocation issuer signature
  V->>V: Reject matching credential digest
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credential.info is visible to the issuer during signing. credential.blind_msg is hidden from the issuer during signing and disclosed in the final credential.