Cryptographically strong random number generation using integrated CMOS photodiodes for low-cost microcontroller based applications

In this work, we propose a method to generate random numbers for low-cost, low-power, resource-limited low data-rate microcontrollers using integrated CMOS photodiodes. The proposed method utilizes an integrated CMOS photodiode in the photovoltaic mode as the entropy source. The method is based on serially capturing analog values derived from the integrated CMOS photodiode. The entropy of these values increased by a custom algorithm. The proposed random number generator is devised using an integrated CMOS photodiode manufactured in 180 nm standard CMOS technology. The wide applicably of the random number generator is demonstrated by realizing it on a low-cost Arduino UNO board placed in a typical room environment. The implemented random number generator passes NIST-SP800-22 and AIS31 randomness tests at high scores. The proposed method achieved 5.4 Kbps throughput and 7.2% total significance level without any postprocessing. The test results show the high cryptographical strength of the proposed method makes it a promising alternative to the currently used random number generation algorithms in low-cost, low-resources, low-data rate microcontroller-based applications.