Abstract: A random-check generator for generating a random number, which is preferably represented in binary form, having a particle source, a random-check generating element which acts on particles emitted by the particle source, and a detection system which allocates a numerical value, preferably in binary form, to the detection of a particle emerging from the random-check generating element. The random-check generator is not susceptible to external interference and delivers high-quality random numbers. To that end, the particle source can emit at least two particles substantially simultaneously, and one particle can activate the detection system in order to detect a further particle influenced by the random-check generating element and allocate a numerical value thereto.