Using a PC camera to generate cryptographically strong random numbers

Random quantities such as passwords and cryptographic keys are extensively used in computer security systems. Algorithmic methods can be used to generate pseudorandom quantities but other methods are preferred to ensure cryptographic strength. This paper presents a method for generating random bits from images or snapshots obtained using a low-quality PC camera. The color information is mixed with clock information to generate bit streams, which are then subjected to a hashing process using SHA-1. Results from using the NIST statistical test suite for randomness show that the random bit generator produces cryptographically strong random bits