A New Lorenz System Parameter Determination Method and Applications

摘要

This paper describes how to determine the parameter values of the chaoticLorenz system from one of its variables waveform. The geometrical properties ofthe system are used firstly to reduce the parameter search space. Then, asynchronization-based approach, with the help of the same geometricalproperties as coincidence criteria, is implemented to determine the parametervalues with the wanted accuracy. The method is not affected by a moderateamount of noise in the waveform. As way of example of its effectiveness, themethod is applied to figure out directly from the ciphertext the secret keys oftwo-channel chaotic cryptosystems using the variable $z$ as a synchronizationsignal, based on the ultimate state projective chaos synchronization.