A Distributed Identifier (DID) is a new type of identifier designed to enable individuals, organizations, and devices to have verifiable, self-controlled digital identities.
Unlike traditional identifiers (such as usernames or email addresses), a DID is decentralized-it does not rely on a central authority or registry. Instead, it is registered and resolved through decentralized networks like blockchains or distributed ledgers.
Key Characteristics
- Globally Unique: Each DID uniquely identifies a subject (person, organization, object, etc.).
- Self-Sovereign: The owner of the DID has full control over it, including the ability to create, update, and deactivate it.
- Cryptographically Verifiable: A DID is associated with a DID Document that contains public keys and other metadata necessary for verification.
- Interoperable: DIDs follow open standards (W3C) and can be used across different platforms and ecosystems.
- Privacy-Respecting: Users can generate multiple DIDs for different contexts, limiting the possibility of unwanted tracking or correlation.
How It Works
- Creation: A user or system generates a DID along with its cryptographic keys.
- Publication: The DID (and optionally its associated DID Document) is published to a decentralized network.
- Resolution: Anyone can look up the DID to retrieve the DID Document, which includes the information necessary to verify the identity or establish a secure communication channel.
- Authentication and Authorization: The public keys in the DID Document allow others to verify that the holder of the DID is indeed the authorized party.
Example
A DID might look like this:
did:example:123456789abcdefghi
This string indicates:
- The method used (
example) - A unique identifier (
123456789abcdefghi)
The method determines how the DID is created and resolved on a specific decentralized system.
Use Cases
- Digital identity for individuals and organizations
- Secure and verifiable logins without passwords
- Device identities in IoT networks
- Data sharing and access control
- Verifiable Credentials and digital certifications
Related Concepts
- DID Document: A JSON-LD file that describes how to use the DID, including public keys and endpoints.
- Verifiable Credential (VC): A digital credential that can be linked to a DID and verified cryptographically.