Security analysis and improvement of the pseudo-random number generator based on quantum chaotic map

In this paper, a security analysis of the pseudo-random number generator based on quantum chaotic map is made, which reveals the existence of serious security problems. Security analysis revealed that more than 99% of the key space is composed of weak keys. Also, normalization of initial condition and relations between control parameters and initial conditions significantly reduce security of the analyzed pseudo-random number generator (PRNG). Observation of only three iterates of the analyzed PRNG allows significant reduction in required complexity of the brute-force attack. All attacks based on weak keys have complexity which is less than $$2^{128}$$2128. For these reasons, analyzed PRNG cannot be considered safe for the use in cryptographic systems. In order to eliminate perceived security problems, improved version of the analyzed PRNG is proposed.