2.2 Triple DES
Triple DES was developed to address the obvious
flaws in DES without designing a whole new
cryptosystem. Triple DES simply extends the key size of
DES by applying the algorithm three times in succession
with three different keys. The combined key size is thus
168 bits (3 times 56), beyond the reach of brute-force
techniques such as those used by the EFF DES Cracker.
Triple DES has always been regarded with some
suspicion, since the original algorithm was never
designed to be used in this way, but no serious flaws
have been uncovered in its design, and it is today
available cryptosystem used in a number of Internet
protocols[8],[9].