Design and Efficient Implementation of a Chaos-based Stream Cipher

International audienceWe designed and implemented a stream cipher cryptosystem based on anecient chaotic generator of nite computing precision (N = 32). The proposed structureof the chaotic generator is formed by a Key-Setup, an IV-Setup, a non-Volatile memory,an output and an internal state function. The chaotic generator uses internal feedbackmode and the generated keystream is used for secure stream ciphers. The cryptographiccomplexity mainly lies in the internal state containing two recursive lters, with one,two or three delays. Each recursive lter includes a perturbation technique using a linearfeedback shift register (LFSR). The rst recursive lter includes a discrete skew tentmap, and the second one includes a discrete piecewise linear chaotic map (PWLCM). Thechaotic generator is implemented in sequential and parallel versions using Pthread library.The proposed Stream ciphers have a very good performance in terms of security andexecution time. The parallel version of the proposed chaos-based stream cipher is fasterthan the eSTREAMS project, and other known chaos-based stream cipher when size ofdata is big. Security performance of chaos-based stream cipher is analyzed, cryptanalyticanalysis and statistical tests such as Histogram with Chi-square test, correlation and NISTtest are applied. Experimental results highlight the robustness of proposed system. Thesecurity of the implemented stream ciphers is investigated by applying several softwaresecurity tools