In a public key infrastructure (PKI), which of the following may be relied upon to prove that an online
transaction was authorized by a specific customer?
Nonrepudiation, achieved through the use of digital signatures, prevents the claimed sender from
later denying that they generated and sent the message. Encryption may protect the data
transmitted over the Internet, but may not prove that the transactions were made. Authentication is
necessary to establish the identification of all parties to a communication. Integrity ensures that
transactions are accurate but does not provide the identification of the customer.