Abstract: Linear Feedback Shift Registers (LFSR) are considered powerful methods for generating pseudo-random bits in cryptography algorithm applications. In this paper, it is shown that linear dependencies in generated random bit sequences can be controlled by adding a chaotic logistic map to LFSR systems. The structure of the LFSR output sequence in combination with a chaotic map is analyzed and found to have at least as much uniformity as the corresponding ensemble for the linear components individually. In order to understand that the use of the proposed PRBG is reliable in secure algorithms, the tests of the NIST suite were carried out on the proposed method, finally to compare the characteristics of the proposed PRNG output sequence with the two types of LFSR ( Fibonacci and Galois).Keywords: Linear feedback shift register, random number, chaotic map, NIST.1. IntroductionIn the modern IT world, network security is the main concern which relies on the use of cryptography algorithms. High-quality random number generation is a fundamental subject of cryptography algorithms and the importance of secure random number generator design cannot be underestimated. The most common generation techniques for RNGs involve truly random and pseudo-random number generators. For a brief introduction to the different types of RNG: Truly random number generators (RNG) are a computer algorithm that generates a sequence of statistically independent random numbers. In fact, these generators require a natural source of random phenomena (i.e. a non-deterministic system). Most practical implementations design a hardware device or software program based on RNGs to produce a statistically independent sequence of bits. Pseud...... middle of paper ......3245, 0.9966745]; so the p-values ​​of our proposed method are within this range, then all 15 tests of the NIST suite were passed, as shown in Figure 6.Fig. 6. NIST test result (red is the proposed PRNG, blue represents Galois and green is Fibonacci)6. ConclusionIn this paper, we presented a new method to generate a sequence of random bits by combining the LFSR system and a chaotic logistic map and it was proved in a reliable theorem. At the end, we compared it with the same other methods such as Fibonacci LFSR and Galois LFSR, and the result was presented in Table 1. AcknowledgmentsThe author would like to thank the editor Professor G.Najafpour, Dr. H. Hassanpour and my teacher Mr. . H.Rahimov for their valuable comments. In the end, one should appreciate the efforts of ITC Research Center at Shahrood University of Technology..