Abstract:
In symmetric cryptosystems a primary key is used to create a number
of subkeys according to specified key scheduling algorithm; certain initial
keys are weak keys. The initial value is split into two halves, and each half is
shifted independently. If all the bits in each half are either 0 or 1, then the key
used for any cycle of the algorithm is the same for all the cycles of the
algorithm This can occur if the key is entirely 1s, entirely 0s, or if one half of
the key is entirely 1s and the other half is entirely 0s.for this reason the design
of a good key schedule is a crucial aspect of cipher design. In This research
presents new algorithms that simplify the creation and expansion process of
the encryption key of the DES algorithm, which is considered one of the most
important elements in the process of encryption, by creating new key
generator architectures that allows us to generate pseudorandom 16 different
keys to be used in cryptographic, algorithm suitable for hardware or software
implementations.These changes, based on genetic algorithm, Simulation
study shows that the proposed technique gives a totally different group of
pseudorandom subkeys each time we run the generator. Furthermore;
comparison analyses between the proposed subkey generation process and the
standard technique used in DES. The proposed method is then been evaluated
and subjected to many randomness tests in order to measures it is strength. A
file has been encrypted using proposed method and the standard technique
used in DES, then the randomness of each one is been subjected to test using
Statistical Test Suite (STS). The result show that the proposed method gives
good result and can be used in future in many cipher for keys generation.
