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Claims

As KILT is an open system, entities can make claims about any other entities, including themselves. An entity can only trust a claim (as in the real world) if another trusted entity (called Attesters) certifies this claim. Therefore, Verifiers might trust different Attesters for distinct scenarios.

Role recap
  • Claimers want information about themselves certified. They also issue credentials, but these remain invalid without an attestation.
  • Attester check the truthfulness of a claim and certify them.
  • Verifiers accept the credentials, only verifying that your certification are legitimate.

Creating a claim​

In KILT, claims are based on claim types (CTypes). Given a CType, a Claimer only needs to create a claim with the properties specified in the CType schema. The resulting claim contains a reference to the CType by its hash and includes the identity of the claim subject (identified by the owner property, which has the value of a KILT DID).

Claim example
{
  "cTypeHash": "0x4f1d68ac46daf4613181b33b16faaf10cf94879dc2246d7485dc2ccbb843641d",
  "contents": {
    "name": "Alice",
    "age": 29
  },
  "owner": "did:kilt:4qWb21mMmWjbgsVuQPJ1f9VFQMbyZwDSFC5wTzJZC91ehVam"
}

Requesting a credential​

Once the Claimer has wrapped their claims into a Credential, they send it to the chosen Attester using any messaging system for certification, i.e. attested.

The to-be-attested Credential contains the original claim, data needed for future selective disclosure of the claim contents (read more in the Verification documentation), and the legitimation and / or delegation ID of the Attester and the credential root hash, used to identify both the credential and its on-chain attestation.

info

For a detailed developer-oriented guide to KILT claims, read the Claim Cookbook section.