Fast Physical Random Bit Generator With Dynamic Post-Processing Based on a Semiconductor Laser Under Multi-Path Optical Feedback

Based on a semiconductor laser (SL) under multi-path optical feedback (MPOF) system, a novel post-processing method for fast physical random bit generation has been proposed and demonstrated. The novel post-processing method is called self-circulating exclusive-or (XOR), and through this post-processing method, all bits of samples are used to produce physical random bits which can pass the National Institute of Standard Technology (NIST) statistical tests and triple standard deviation tests. For the chaotic source of a SL under MPOF system, the influences of feedback intensity on time-delay-signature (TDS) and bandwidth of the produced chaotic signal are experimentally analyzed. The experimental results show that a low TDS chaotic signal with 13 GHz bandwidth can be obtained under appropriate operating parameters and $8\times 80$ Gb/s statistically passable physical random bits are produced by using the self-circulating XOR method. In addition, the self-circulating XOR method is robust to the number of samples in delay XOR loop and has a great potential to implement by using up-to-date electronic devices.