KILT provides a language for the description of arbitrary characteristics of persons, organisations and things. Communication about claimed characteristics is standardised by Claim Types (CTYPEs).

As Claimer, Attester and Verifier communicate about the characteristic when it has been claimed, its content needs to be equally understandable for the three of them. On the KILT Blockchain, claims are standardised through CTYPEs, a concept exclusively invented for KILT.

CTYPEs describe the content and structure of a claim. For a claim about a person, the CTYPE could be “age”, for a claim about a thing it could be “energy efficiency class”. If we take the example of a driver’s licence, the CTYPEs may represent the fields “name”, “driving licence class” and “issue date”.

Everyone is authorised to create their own CTYPEs free of charge and use CTYPEs that have already been created. If an Attester issues many credentials of a certain CTYPE which is then used by other Attesters they increase their chances of winning the “block reward”, an incentivisation mechanism in the form of KILT Coins.

One overriding goal of the KILT Blockchain is the standardisation of CTYPEs and thus allowing market participants to build investment-safe software.