Utility.Credential.V0.Credential

Templates

template Credential

A credential contract issued by an issuer to a holder for a specific purpose. It allows an issuer to attest a fact about a subject. The subject is typically the same as the holder of the credential. Credentials should be immutable, so that they can be fetched (i.e. verified) without contention. Credentials can be configured to be existential: by not providing an expiry date, they are valid as long as the contract exists on ledger.

Signatory: issuer, holder

Field	Type	Description
issuer	Party	Issuer of the credential.
holder	Party	Holder of the credential.
id	Text	Identifier of the credential.
description	Text	Description of the credential.
validFrom	Optional Time	Timestamp as of which the credential becomes valid. If not provided, the credential becomes valid as soon as it is created.
validUntil	Optional Time	Timestamp as of which the credential ceases to be valid. If not provided, the credential is valid indefinitely (or until it is revoked). Since credentials should be immutable, it is recommended to only provide this timestamp if it is guaranteed to stay constant. For example, paid credentials should typically have None here, because the initial validity period could either be extended (if the user tops up their balance) or shortened (if the USD vs CC rate changes).
claims	{ref}[Claim <type-utility-credential-v0-credential-claim-45224>]	A list of claims, which are statements about a subject. The subject is typically the same as the holder of the credential.
observers	Parties	Observers of the credential.

• Choice Archive

  Controller: issuer, holder

  Returns: ()

  (no fields)

• Choice Credential\_Get

  Fetch the credential.

  Controller: actor

  Returns: Credential\_Get\_Result

  Field	Type	Description
  actor	Party	The actor party.

• Choice Credential\_Revoke

  Revoke the credential.

  Controller: actor

  Returns: Credential\_Revoke\_Result

  Field	Type	Description
  actor	Party	Revoker of the credential: This can either be the issuer or the holder.

Data Types

data Claim

A claim is a statement about a subject. Reference: https://www.w3.org/TR/vc-data-model-2.0/#claims (terminology therein used below) For example: “Pat is an alumni of XYZ University”.

Claim

Field	Type	Description
subject	Text	A subject is a thing about which claims can be made (“Pat” in the example above).
property	Text	Property of the claim (“alumniOf” in the example above).
value	Text	Value of the claim property (“XYZ University” in the example above).

data Credential\_Get\_Result

Result of Credential_Get.

Credential\_Get\_Result

Field	Type	Description
credential	Credential	The fetched credential.

data Credential\_Revoke\_Result

Result of Credential_Revoke.

Credential\_Revoke\_Result

(no fields)

type Parties

= Set Party

Type synonym for a set of parties.

data PartyCredentialRequirement

Defines the criteria a credential must satisfy to prove authorization for a Party (the subject). The validation will additionally check that the credential is held by either the subject or the issuer.

NOTE: This data type is used internally by Utility applications. External consumers should use their own credential requirement definitions (as these might evolve independently).

PartyCredentialRequirement

Field	Type	Description
issuer	Party	Required issuer of the credential.
requiredClaims	[(Text, Text)]	Required (property, value) pairs. Each must exist in the credential as a claim where the subject is the claim’s subject.