Digital random number generator based on digitally-controlled oscillators

A system for random number generation includes a digital oscillator circuit, which has a set of available configurations and is operative to generate a random number sequence in accordance with a current configuration selected from the set. The system further includes a randomization circuit, which is operative to produce a pseudo-random stream of values corresponding to the available configurations of the digital oscillator circuit, and to control the digital oscillator circuit to alternate among the available configurations in accordance with the pseudo-random stream of values.