Logistic chaotic maps for binary numbers generations

Two pseudorandom binary sequence generators, based oil logistic chaotic maps intended for stream cipher applications, are proposed. The first is based oil a single one-dimensional logistic map which exhibits random, noise-like properties at given certain parameter values, and the second is based on a combination of two logistic maps. The encryption step proposed in both algorithms consists of a simple bitwise XOR operation of the plaintext binary sequence with the keystream binary sequence to produce the ciphertext binary sequence. A threshold function is applied to convert the floating-point iterates into binary form. Experimental results show that the produced sequences possess high linear complexity and very good statistical properties. The systems are put forward for security evaluation by the cryptographic committees. (C) 2007 Elsevier Ltd. All rights reserved.