'authenticator' originates from Late Latin, specifically the word 'authenticare' (from Latin 'authenticus'), ultimately from Greek 'authentikos', where 'authent-' meant 'genuine' or 'authoritative'.

'authenticator' developed from the verb 'authenticate' (Middle English/late formation from Medieval Latin 'authenticare'), with the agentive suffix '-or' later creating the noun meaning 'one that authenticates' and, in modern usage, also naming devices that perform authentication.

Initially associated with certifying or making something genuine (a person or act of certification); over time it expanded to include technological meanings — devices, tokens, or software that perform identity verification.