Attack and construction of simulator for some cipher systems using neuro-Identifier

The problem in cryptanalysis can be described as an unknown and the neural networks are ideal tools for blackbox system identification. In this paper, a mathematical black-box model is developed and system identification techniques are combined with adaptive system techniques, to construct the Neuro-Identifier. The Neuro-Identifier is discussed as a black-box model to attack the target cipher systems. In this paper a new addition in cryptography. Has been presented, and the methods of classical and stream cryptosystems are discussed. The constructing of Neuro-Identifier mode is to achieve two objectives: the first one is to emulator construction Neuro-model for the target cipher system, while the second is to (cryptanalysis) determine the key from given plaintext-ciphertext pair.