Security performances of a chaotic cryptosystem

We present here the security performances of a chaotic cryptosystem implemented on DSP. We have attached ourselves to one encryption scheme using the chaotic dynamics of two-dimensional noninvertible maps. As the nonlinearity of the map, even associated to the sensitivity to initial conditions, does not guarantee the security of the system, the encryption law combines three properties of chaos. The implementation of this algorithm had been realized on DSP. This realization had demonstrated first that the cryptosystem works properly, and then had shown very important computing times for brute force attacks. In this paper, we describe the results obtained through a more complete cryptanalytic study, and we detail the different characteristics needed for the chaotic maps, to ensure security of the cryptosystem.