Efficient random number generation techniques for CMOS SPAD array based devices

Abstract

This work presents new techniques to produce true random bits by exploiting single photon time of arrival. Two FPGA-based QRNG devices are presented: Randy which uses one discrete SPAD and LinoSPAD which uses a CMOS SPAD array, along with a time-to-digital converter (TDC). Post-processing procedures are explained in order to extract randomness taking care of SPAD and TDC non-idealities. These procedures are based on the application of Peres [Y. Peres, Ann. Statist.20, 590 (1992)] and Zhou-Bruk [H. Zhou and J. Bruck, arXiv:1209.0726 (2012)] extraction algorithms. Achieved generation rates are 1.8 Mbit/s for Randy device and 310 Mbit/s for LinoSPAD device. Randy QRNG also features a real time procedure which was used for the realization of fundamental tests of physics.