Putting the Claimer in control means the attester is no longer involved in the Verification process. That would cause injustice for users data in several cases.
Kilt solves the dilemma by typing a hash of attestation onto the blockchain, thus fulfilling a notary function & enabling credential revocations.
In case of an on-chain Attestation, four pieces of information are written onto the blockchain:
● Public key of the Attester
● Hash of the Claim that is being attested
● Signature of the Attester
● Placeholder field to mark if the Attestation is revoked later