In most situations pseudo-random numbers produced by computer software (“random” number generators) are good enough as long as we are careful when choosing the seed for the generator. Sometimes, it can be even an advantage to be able to reproduce sequences of pseudo-random numbers by setting the seed value. Frequently, the seed is obtained from the clock of the computer, e.g. using the seconds or milliseconds digits from current time. This is still not truly random, as random numbers cannot be generated by any deterministic process. True random numbers can be only be generated by a random physical process.