Which one of the following is an accepted practice for providing strong encryption services?

A.
Maintaining the secrecy of the algorithms used

B.
Use of a large keyspace to provide a greater variety of keys

C.
Use of a smaller keyspace to provide the ability to choose a strong key

D.
Make sure the plaintext itself is not hard to guess

Explanation:
The strength of the encryption method comes from the algorithm,
secrecy of the key, length of the key, etc. The secrecy of the key is maintained by
having a larger keyspace to construct a key, thus making it harder to derive the
secret key.