A random number generating system for generating a sequence of random numbers comprising a memory, the memory being writable, volatile and configured such that the memory contains an at least partially random memory content upon each powering-up of the memory, an instantiating unit configured for seeding the random number generating system with a seed dependent upon the at least partially random memory content, the sequence of random numbers being generated in dependence upon the seed, and an over-writing unit configured for over-writing at least part of the memory with random numbers generated by the random number generating system in dependence upon the seed.