Making proper randomness

Random number generation is an indispensable technology for secure communications. We developed a random number generator that utilizes the irregular fluctuations of a semiconductor laser output as the randomness source, thus achieving a gigabit per second generation rate. In addition to their lack of bias, the unpredictability of generated random numbers is of crucial importance for ultimate security. We therefore verify experimentally that our random number generator work in accordance with the theory explaining the origin of its unpredictability. Our research aims to extend the applicability of our system in a secure information and communication service environment by establishing a solid basis guaranteeing the quality of generated random numbers.