Which of the following is the MOST appropriate method to protect a password that opens a confidential file?

A. Delivery path tracing

B. Reverse lookup translation

C. Out-of-band channels

D. Digital signatures

Explanation:

Out-of-band channels are useful when it is necessary, for confidentiality, to break a message into two parts that are then sent by different means. Digital signatures only provide nonrepudiation. Reverse lookup translation involves converting; in Internet Protocol (IP) address to a username. Delivery path tracing shows the route taken but does not confirm the identity of the sender.