Public DID Write Public DIDs are the public identifier of organizations who wish to issue credentials. At a minimum, an organization issuing credentials only needs one DID. If desired, a given organization could have different DIDs for different business units or departments, however in general an organization should only need a relatively small number. This is a one-time registration fee for a permanent DID—there are no renewal fees. Rotating the keys of an existing DID is also $10.