An All-Digital True Random Number Generator Based on Chaotic Cellular Automata Topology

True random number generator (TRNG) is an important primitive in cryptographic applications. In this paper, a TRNG based on a self-timed ring structure is presented, the basic elements of the ring is a realization of a chaotic cellular automata topology. In particular, the proposed TRNG design is fully synthesizable with standard all-digital components. Test chips of the proposed TRNG structure were fabricated with 40nm TSMC technology node, and the utilized overhead is only 75 NAND gates equivalent, with a die area of $270 \mu m^{2}$. Experimental results demonstrated that the TRNG test chips can generate random numbers at a high bit rate: 1600Mb/s. The test sequences generated by the TRNG test chips passed all test statistics of the widely used test suite: NIST SP800-22, as well as the independent and identically distributed (IID) test of NIST SP800-90B.