Which of the following methods of encryption has been proven to be almost unbreakable when correctly used?

A.
key pair

B.
Oakley

C.
certificate

D.
3-DES

E.
one-time pad

F.
None of the choices.

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.