Which of the following encryption methods uses a matching pair of key-codes, securely distributed, which are used once-and-only-once to encode and decode a single message?

A. Blowfish

B. Tripwire

C. certificate

D. DES

E. one-time pad

F. None of the choices.

Explanation:

Its possible to protect messages in transit by means of cryptography. One method of encryption – the one-time pad – has been proven to be unbreakable when correctly used. This method uses a matching pair of key- codes, securely distributed, which are used once-and-only-once to encode and decode a single message. Note that this method is difficult to use securely, and is highly inconvenient as well.