  Pseudo-Random Bit Generation (PRBG) is required in many aspects of
cryptography as well as in other applications of modern security engineering.
In this work, PRBG based on 2D symmetrical chaotic mappings of logistic type is
considered. The sequences generated with a chaotic PRBG of this type, are
statistically tested and the computational effectiveness of the generators is
estimated. Considering this PRBG valid for cryptography, the size of the
available key space is also calculated. Different cryptographic applications
can be suitable to this PRBG, being a stream cipher probably the most immediate
of them.
