ABSTRACT
Encryption along with hashing algorithms can also be
used to authenticate the traffic between two network con-
nections. Two types of encryption algorithms are utilized
to encrypt network traffic: symmetric and asymmetric.
Symmetric algorithms use a shared key that is known to
both parties to encrypt the traffic. They are much faster and
require fewer computing resources than asymmetric algo-
rithms. Algorithms of this type include the Advanced
Encryption Standard (AES) and Triple-DES (formed
from the Data Encryption Standard). An important factor
in the implementation of symmetric encryption is the size
of the shared keys that are being used. The size of this key
determines the key space or range of values that the key can
have. The size of the key space is an important factor in
determining the strength of the implementation of an
encryption system. One type of attack, called a brute
force attack, attempts to decrypt the encrypted data by
trying every possible key value in the key space. Larger
key sizes are used to provide more protection against these
attacks. It is important that the key space be of sufficient
size so the amount of time and resources required to
attempt all of the keys in the key space is large enough to
make it impractical to try.
