Definitions Authentication a claimant tries to show a verifier that the claimant is as declared identification Different from message authentication which enables the recipient to verify that messages have not been tampered with in transit data integrity) and that they originate from the expected sender(authenticity) 復大辱软件学院4 Definitions Authentication: • A claimant tries to show a verifier that the claimant is as declared – identification • Different from message authentication – which enables the recipient to verify that messages have not been tampered with in transit (data integrity) and that they originate from the expected sender (authenticity)