What is Authentication?
Authentication is the verification of the identification of an individual. Authentication generally comes before authorization.
Under the GDPR, recital 57, a data controller is obliged to authenticate the identity of a data subject in order to support the exercise of the data subject’s rights.
Authentication is relevant to the CIPT certification. See the CIPT Body of Knowledge: IV. Privacy in systems and applications, B. Identity and access management: https://iapp.org/media/pdf/certification/CIPT_BOK_2.1.2.pdf