How many bits make up the effective DES key?

A.
56

B.
64

C.
32

D.
16

Explanation:
DES has a key size of 64-bits, but 8 bits are used for parity, so the
true key size is 56 bits. Remember that DEA is the algorithm used for the DES
standard so DEA has a true key size of 56 bits also because we are actually talking
about the same algorithm here. DES is really the standard and DEA is the algorithm,
we just call it DES in the industry because it is easier.