  For data ciphering a key is usually needed as a base, so it is indispensable
to have one that is strong and trustworthy, so as to keep others from accessing
the ciphered data. This requires a pseudo-random number generator that would
provide such a key, so it is proposed to work with cellular automata helped
along with \emph{Mathematica} to check that the rules and to what level are
actually pseudo-random. This project centers on the examination of possible
mathematical rules, analyzing their characteristics in a detailed manner, and
submitting them to a set of randomness tests with the end of knowing which of
them will enable us to obtain those pseudo-random numbers that will conform the
key for data ciphering.
