Non-repudiation

In law, non-repudiation is a situation where a statement's author cannot successfully dispute its authorship or the validity of an associated contract.[7] Message Authentication Codes (MAC), useful when the communicating parties have arranged to use a shared secret that they both possess, does not give non-repudiation.Note that the goal is not to achieve confidentiality: in both cases (MAC or digital signature), one simply appends a tag to the otherwise plaintext, visible message.A notary is a witness who verifies an individual's identity by checking other credentials and affixing their certification that the person signing is who they claim to be.A notary provides the extra benefit of maintaining independent logs of their transactions, complete with the types of credentials checked, and another signature that can be verified by the forensic analyst.
contractchequethe cheque is a forgerydigital signatureskey card accessdigital securityintegrityorigin of datadata in transitman-in-the-middle attackphishingmutually authenticatedMessage Authentication Codes (MAC)encryptionauthenticated encryptionTrustedtrusted third partyforensic analystsnotariescertificate authoritypublic key certificatessmart cardsUnited States Department of DefenseCommon Access Cardpersonal identification numberPlausible deniabilityDesignated verifier signatureInformation securityUndeniable signatureProQuest