Research And Design Of True Random Number Generator

With the rapid development of social information technology,data storage and exchange become more and more frequent,people paying more attention to the security of data storage,and the quality of the random number determines the security of the encryption system.The purpose of this paper is to design and implement a high-speed digital true random number generator(TRNG)only consisting of ordinary logic elements,and the speed of random number generation is over 100 Mbit/s.In addition,the output of random number sequence should achieve NIST SP800-22 certification.TRNG is usually composed of entropy source module and post-processing module.The entropy source module uses some unpredictable physical phenomena as a random source,and the postprocessing module is mainly used to reduce or eliminate the output sequence offset and correlation.This paper analyzes the reasons for the restriction of the output rate of TRNG.On the basis,we proposed a structure composed of multiplexer to speed up the sampling rate by superimposing the independent entropy source,and this structure can reduce the correlation between the sampling sequences by rotating the sampling of multiple independent entropy sources,and accelerating the random number generation rate.Based on this improved structure,the traditional metastable entropy source and oscillation jitter entropy source are modified accordingly,then it used as the final entropy source module.The post-processing module used an XOR chain circuit to reduce the bias existing in the sequence,and the random numbers generated by the two types of entropy sources are reassembled by the DES algorithm.Compared with the TRNG of single entropy source,the random number generation rate can be improved obviously in this paper.At the same time,because of the non-linear operation DES algorithm,the generator's anti-attack ability has been promoted.In order to verify the effectiveness of the design,the TRNG be implemented in Altera Cyclone IV EP4CEl5F17C8 FPGA platform.The final results of the TRNG were verified by the NIST SP800-22 random number test suite and the results showed that the random number sequence generated by the TRNG can be verified by the NIST SP800-22 standard stably below 300 MHz system clock.Additionally,there are total of 1.247 logic units are occupied,the highest output rate of this TRNG achived 299.52 MHz.Compared with other digital random number generators of the same type,the output rate of the TRNG is greatly improved when the resource consumption is medium.