Private Key

A private key is an essential part of a digital identity, often represented by a Decentralized Identifier (DID). A DID is a unique identifier that is cryptographically secured and can be used to verify the identity of an entity (e.g., a person, organisation, or device).

When an issuer (e.g., a university, employer, or government agency) issues a verifiable credential, it uses its private key to sign the credential. This digital signature ensures that the credential is authentic and has not been tampered with.

For an individual or entity to prove ownership of a DID, they use their private key to sign a challenge or request. This signed message can be verified by others using the corresponding public key, confirming the identity of the signer.

When a holder (e.g., an employee or student) needs to present a verifiable credential to a verifier (e.g., an employer or service provider), they use their private key to sign the credential presentation. This proves that the credential is being presented by the rightful owner.

Verifiers use the issuer's public key to verify the signature on the credential. They also use the holder's public key to verify the signature on the credential presentation. This process ensures that the credential is valid and has been presented by the rightful holder.