Research Of On-chip True Random Number Generator

The requirement of high quality random numbers grows day by day, which results in true random number generator takes great attentions; And the appearance and development of system on a chip needs the realization of on-chip random number generator. Considering the two facts, this paper comes up with a new method of random number generator based on the noise source of Phase Locked Loop(PLL). The method can provide good properties: true randomness and easy to realization and system integration.This method has four significant merits: l)source of noise derives from physic phenomenon-jitter of PLL instead of free-running oscillator; 2) the primary data are processed by a Von Neumann corrector, which removes the bias and improves the randomness of the data; 3)digital post-processing introduces secure hash arithmetic(SHA-1),which betters the statistic property of output of the random number generator; 4) a specially developed hash plan prompts hash process running under two modes, which can assure that the generator possess true randomness and have a stable production of random numbers.In this paper, we have completed the design and test of a true random number generator based on PLL. Furthermore, we get a conclusion about the properties of the generator by analyzing the statistic test results of the random outputs.It is an experiment of realizing random number generator based on PLL, whose result can be referred by developers of system chip, embedded system or high-quality random number generator.