What term describes the function of digital signatures related to proving that the signature was provided by the owner of a given private key?

A feature of digital signatures is nonrepudiation. A signed file or message can be proven to be from the signer, proving that it is legitimate. Key stretching describes techniques used to make it harder to crack weak keys. Authentication is the process of validating that a person is who they say they are but is not specific to digital signatures. Ledger-based validation was made up for this question.