The Verifiable Credential Status List v2021 Specification is a working document from the W3C to support a privacy-preserving, space-efficient, and high-performance mechanism for publishing status information such as suspension or revocation of JSON and JSON-LD Verifiable Credentials.
Using DID-Linked Resources, we have been able to natively support Status List 2021 on cheqd directly.
| Create Status List | Create a Status List on-ledger as a DID-Linked Resource using Veramo | statuslist2021-resources.md |
| Status List within a Verifiable Credential | Issue a Verifiable Credential with a cheqd Status List within the body. | issuing-a-verifiable-credential-referencing-status-list.md |
The Status List 2021 Specification utilises bitstrings to represent whether a Verifiable Credential has been suspended/revoked or not. A bitstring can be thought of as a long list of 1s and 0s, where, if the binary value of the position in the list is 1 (one), the verifiable credential is revoked, if it is 0 (zero) it is not revoked.
Figure 1: Graphic showing the StatusList2021 bitstring
Each issued Credential correlates with a position and index on the bitstring, so that a verifier will be able to correlate the value within the Credential against the public bitstring to ascertain whether the Credential has been revoked or not, using a validate algorithm as well as a bitstring expansion algorithm.
The issuer keeps a bitstring list of all Verifiable Credentials it has issued. The StatusList is usually published by the issuer in the format of its own Verifiable Credential. This Verifiable Credential is generally hosted publicly on a centralised server or domain to enable third-party read-access.
cheqd stores each Status List and subsequent entries on-ledger as DID-Linked Resource versions. This has notable benefits, including the provenance, legitimacy and security of the Status List. For a full list of benefits, see the context for creating DID-Linked Resources.
Below are a list of alternatives for creating cheqd Status Lists.
| cheqd Studio | Our API product enables users to use cheqd's functionality with minimal complexity and easily integrate APIs into existing apps. | studio |
| DID Registrar | Simple setup for building cheqd DIDs into existing applications using REST APIs, building into the Universal Registrar. | did-registrar |