A random number generator (RNG) is an electronic circuit that continuously generates random numbers. These are numbers that are neither predictable nor reproducible. Depending on their function, random number generators work with a Linear Feedback Shift Register
(LFSR), which is ideal for generating random numbers. Other random number generators derive their random numbers from statistical events or physical processes. This can be noise in its various forms, it can be atomic decay products or some other signal derived from a stochastic process. The conversion of a stochastic signal into a random number could be done via a sensitive amplifier circuit in which noise is amplified. A downstream Schmitt trigger generates the random voltage spikes. The pulses present at the output of the Schmitt trigger could be converted to a random number in a counter
with a gate function. If a binary value is output instead of the random number, this is referred to as a random bit
generator (RBG). Random bit
generators are used wherever security and authentication are involved, such as in passphrases, gambling numbers, in encryption procedures, in hardware security modules (HSM) or in scrambling.