Attack on a chaos-based “true” random bit generator

This paper presents an algebraic attack on a chaos-based “true” random bit generator (RBG). A clone system is proposed to analyze the security weaknesses of the RBG and its convergence is proved using master slave synchronization scheme. Secret parameters of the RBG are revealed where the only information available are the structure of the RBG and a scalar time series observed from the chaotic oscillator. Simulation and numerical results verifying the feasibility of the clone system are given. The RBG doesn´t fulfill Diehard and NIST-800-22 statistical test suites, not only the next bit but also the same output bit stream of the RBG can be reproduced.