28Eki
Do integrity and authentication always come together?
I cannot come up with a case where there is only one of them.
When there is integrity, a random person cannot modify the message without being noticed. That is, an unauthenticated user cannot modify the message without being noticed. Therefore there is authentication.
When there is authentication, nobody except the sender can change the message after MAC or signature is added. Therefore there is integrity.
Am I missing something?
