Bob, your senior colleague, has sent you a mail regarding aa deal with one of the clients. You are requested to accept the offer and you oblige. After 2 days, Bob denies that he had ever sent a…

Confidentiality ensures information is accessible only to authorized parties, but provides no proof of who performed a specific action.

Integrity ensures data was not altered in transit, but does not create an undeniable record attributing an action to a specific sender.

Non-repudiation ensures that the originator of a message cannot later deny having sent it, typically enforced through digital signatures bound to the sender's private key. In this scenario, a valid digital signature on Bob's email would cryptographically prove he sent it, since only his private key could produce that signature.

Authentication verifies identity at a point in time but does not produce a persistent, legally binding proof that a specific action was taken.