A metastability-based true random number generator on FPGA

True random number generators (TRNGs) are essential components for a wide range of chips. This paper presents a novel method to design true random number generators on FPGA. By using cross-coupled NAND gates and manual routing, the proposed TRNG is implemented on Xilinx Virtex XC5VLX50T FPGA with a self-calibration and post processing circuit. The proposed TRNG can achieve the random bit rate from 600Kbps to 30Mbps, while consuming 4 LUTs to 220 LUTs. The TNRG passed all NIST tests with high entropy. Compared with other design, the proposed TRNG can achieve high quality of randomness and high throughput rate. Thus, the proposed circuit can be used in true random number generator design on FPGA.