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Abstract
Our work deals with the generation of pseudo-random binary sequences. These sequences are mainly used for spread spectrum systems, cryptosystems-key generation, stream ciphering systems, and code-division multiple-access systems.
A new method for generating pseudo-random binary sequences based on a fuzzy logic system is presented. This method, that we had designed, can be adopted to generate pseudo-random sequences of arbitrary length. In fact, they are of unlimited length, but we limit our work for sequences of length 222 bits. We named this method the Fuzzy Bit Generator (FBG). In addition, an enhanced version of the FBG is presented (EFBG) which improves the security performance of the FBG.
It is shown that these sequences are of good correlation properties.
In addition, the sequences are tested against the National Institute of Standards and Technology (NIST) statistical tests suite and other available testing packages to verify its very good randomness properties. All these features enable the use of this pseudo-random bit generator in all the mentioned fields.
An Image Encryption System is designed. The encryption system uses the FBG sequences as encrypting sequences. The encrypted images are tested against the fractal dimension to verify its disorder appearance.
Finally, a Stream Cipher System on the form of a non-linear feedback shift register is designed. The FBG acts as the non-linear feedback function. The keystream generated is tested against the NIST statistical test suite to ensure its random properties.