By Ashok Baria November 7, 2019
Specialized terminology is used for blockchain-based identity management schemes. Unfortunately, the terminology is not always consistent among the various projects and standards. Further complicating matters is that some domain-specific terms are related to identity management in general while others are specific to blockchain identity management.
With this terminology, we can identify the common roles that occur in blockchain-based IDMSs and the relationships between these roles. We can also identify common objects found in these systems and the relationships between those objects.
Below Figure provides a high-level overview of the identity management roles.
Note that these roles are not exclusive. For instance, a subject and an issuer can both take the requester role or a subject and a verifier can both be a relying party. Depending on the IDMS, the approval of a subject may be required to issue a new credential to that subject.
The next figure provides a high-level overview of the objects that entities interact with in a blockchain IDMS. The figure shows that entities can have one or more identifiers, that identifiers are associated with one or more credentials, and that presentations are derived from credentials.