Determination of the parameters for a Lorenz system and application to break the security of two-channel chaotic cryptosystems

This Letter describes how to determine the parameter of the chaotic Lorenz system used in a two-channel cryptosystem. First the geometrical properties of the Lorenz system are used to reduce the parameter search space. Second the parameters are exactly determined-directly from the ciphertext-through the minimization of the average jamming noise power created by the encryption process.