CISA Certified Information Systems Auditor – Question1794

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.

Correct Answer: E

Explanation:

Explanation:
It’s 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.