Generation of multi-channel high-speed physical random numbers originated from two chaotic signals of mutually coupled semiconductor lasers

We propose and experimentally demonstrate a novel technique to generate multi-channel high-speed physical random numbers (PRNs) by taking two chaotic signal outputs from mutually coupled semiconductor lasers (MC–SLs) as entropy sources. First, through controlling the operation parameters of the MC–SL system, two time-delay signature (TDS) suppressed chaotic signals can be obtained. Next, each of these two chaotic signals is sampled by an 8 bit analog-to-digital converter (ADC) with a sampling rate of 10 GHz, and then a bitwise exclusive-OR (XOR) operation on the corresponding bits in samples of the chaotic signal and its time delayed signal is implemented to obtain 8 bit XOR data. Furthermore, through selecting the five least significant bits (LSBs) of 8 bit XOR data to form 5 bit Boolean sequences, two sets of PRN streams with a rate up to 50 Gbits s⁻¹ are generated and successfully pass the NIST statistical tests. Finally, merging these two sets of 50 Gbits s⁻¹ PRN streams by an interleaving operation, another set of the 100 Gbits s⁻¹ PRN stream, which meets all the quality criteria of NIST statistical tests, is also acquired. (letter)