Verifiable Claims is a draft specification proposes a data model for claims about entities having to do with identity profiles. A claim in the Verifiable Claims system has these elements:
- Issuer (the claim’s author)
- Subject (the entity named in a claim)
- Inspector (the entity who can validate the claim)
- Holder (the entity who controls a claim, which may or may not be the subject entity stated in the claim)
- Context (a mapping to a globally defined semantic in a machine-readable data format)
The specification discusses self-sovereignty briefly but does not provide a solution for this element at this time. The Verifiable Claims architecture document calls for a registry of globally unique identifiers but the specification does not provide a solution for this element at this time.
There is discussion ongoing in the Verifiable Claims community about a formal role for Linked Data.
A “verifiable claim” is a trusted assertion an issuer makes about an entity to a verifier who is authorized to request such validation. More specifically, it is machine-readable statement made by an entity that is cryptographically authentic (non-Repudiation). A “credential” (aka attestation) is defined to be a set of verifiable claims that refer to a qualification, achievement, personal quality, aspect of an identity such as a name, government ID, preferred payment processor, home address, or university degree typically used to indicate suitability. The VCWG was established on the notion that there is currently no widely used user-centric standard for expressing and transacting verifiable claims via the Web. As such the aspects to be standardized by the VCWG are the set of verifiable claims that consists of the Subject Identifier, the Claims (about the subject), and the Claims Set Metadata. All claims are digitally signed by its issuer. The architecture of the proposed verifiable claims ecosystem follows that of the classic “four-corners” model used in the Payment Card industry. An Issuer entity creates a signed claim about a Subject, that is then provided to a Holder entity (which could be the subject itself). The entity that seeks to obtain assurances (regarding a Subject) is referred to as the Inspector. The Holder presents claims to the Inspector who has the option to validate its correct ownership against an Identifier Registry. This registry maintains the set of recognized identifiers in the ecosystem.