A Monolithic Silicon Quantum Random Number Generator Based on Measurement of Photon Detection Time

In this paper, a nondeterministic random number generator based on detection of the single photons emitted by an Si-CMOS-LED light source integrated for the first time on the detector chip is presented and experimentally demonstrated. We use a ring-shaped single-photon avalanche diode (SPAD) around the Si-CMOS-LED fabricated in 0.35-μm HV-CMOS technology to generate random events. The time intervals between single-photon events are independent quantum random variables. A field-programmable gate array (FPGA) digitizes the time variables to the stream of random bits. Bias in the raw data due to the nonuniform distribution of the time intervals is removed by postprocessing in a special configuration of xor gates to improve the randomness of the generated random bits. The quantum random numbers in 1-Gb streams with bit generation rate of 1 Mb/s were directly delivered to a personal computer (PC) and passed all statistical tests from ENT, STS, and DIEHARD, as well as for more accuracy correlation and bias tests applied on these streams.