Authentication allows customers to be sure that the merchant they are sending their credit card details to be who they say they are. It can also allow merchants to verify that the customer is the real owner of the credit card being used. Authentication is provided through digital certificates. Digital certificates provide the basis for secure electronic transactions as they enable all participants in a transaction to quickly and easily verify the identity of the other participants. Integrity ensure that the messages have not been tampered with by a third party during transmission.
Integrity is ensured through encryption.
If information is received that will not decrypt properly then the recipient knows that the information has been tampered with during transmission. Non-repudiation prevents customers or merchants denying they ever received or sent a particular message. Privacy prevents third parties from reading intercepted messages. Privacy is also guaranteed through encryption. Although information can still be intercepted by a third party they will be unable to read them as they have no access to the encryption key.