'authenticator' originates from Late Latin, specifically the verb 'authenticare', where 'authenticus' meant 'original, genuine' and the Latin suffix '-ator' meant 'one who does'.

'authenticator' changed from Middle English forms derived from Old French 'authentifier' and Medieval Latin 'authenticare', and eventually became the Modern English noun 'authenticator' by adding the agentive suffix '-ator' to the verb 'authenticate'.

Initially, it meant 'one who makes or declares something authentic', but over time it evolved into its current meaning of 'a person or device that verifies authenticity'.