Improved Design Of True Random Number Generator Based On DFA

In the last decade or so,the Internet has developed at a speed beyond imagination.Previously,it was all communicated through letters or face to face.Now,it is basically replaced by the Internet.As the Internet has become a part of daily life,so the network information security has been the majority of network users pay close attention to.The security of the information is completely determined by the reliability of the password,and the level of the confidentiality of the password is determined by the complexity of the key.The better the randomness of the random number,the more complex the generated key is.On the contrary,the generated key is relatively simple and easy to be cracked.This paper introduces the port of the Direct Frequency Average(DFA)true random number generator.The true random number generator is divided into two modules.One is the module to generate the random number and the post-processing module to process the generated random number.Since this paper is based on the improvement of DFA true random number generator,the focus of the work is on the post-processing module to deal with the randomness of random number.In addition,this paper describes the entropy source generation methods of some true random number generators,the design of common post-processing modules,and the reliability analysis of 15 test methods in the National Institute of Standards and Technology(NIST)test.The DFA true random number generator before improvement uses the linear feedback shift register as the post-processing module.Although the randomness of the random number processed by the linear feedback shift register is improved,the test results are not very good.Therefore,the post-processing module is improved by adding a linear congruence module and a feedback mechanism.The two improved parts have three combined designs.1.Turn off the feedback mechanism and add only linear congruence module;2.Turn on the feedback mechanism.First,the data generated by the true random number generator is fed back to the frequency control word port of the true random number generator through the feedback mechanism,and then the random number is output through the linear congruence module.3.Turn on the feedback mechanism.The random number generated by the DFA true random number generator is processed by the linear congruence module first,and then fed back to the frequency control word port of the DFA true random number generator.The improved design is implemented on FPGA with Verilog hardware,and the random number is generated through FPGA,and then the randomness of the random number is detected through NIST test.The test results show that the randomness of the third combination design is obviously better than that before the design improvement.