Random number generators – or RNGs for short – are used in thousands of applications that we encounter every single day, from video games to bingo draws. The ability of a computer to randomly generate seemingly infinite but still random sequences of numbers is something that has been instrumental to technological progress over the past 50 years, allowing us to build the codes and architecture on which so much modern technology depends on.

Although a seemingly simple and instantaneous process, the random generation of numbers is actually a complex and interlinked action, often determined by external factors. Here is exactly how RNGs work.

The Basics

The first thing you need to know is that there are two different types of RNGs: Pseudo-Random Numbers Generators (PRNGs) and True Random Number Generators (TRNGs). PRNGs are actually the most common type of sequence used by computers, despite that not being completely random in the same way that say, the roll of a die is.

The sequence produced by the PRNG method is done via algorithms that make use of either mathematical formulas or pre-calculated lists. This has been described by Random.com as being “akin to rolling a die many times and writing down the results”. The order the numbers may appear in are random, but the numbers themselves are not actually random as they already exist in some form prior to generation.

The other type is TRNGs. These can be described as “truly random” because they rely on a random, external factor to generate numbers. A common example, and one reportedly used by security agencies such as GCHQ, is the measuring of the radioactive decay of an atom, which has nothing to do with the computer itself. Since radioactive decay is impossible to determine, it is one of the few things in the universe that is truly random. Other unpredictable, random data a computer can use to generate TRNGs include keystrokes, clicks and atmospheric noise.

How They’re Used

number generator

TRNG’s are commonly used by organisations that need total randomness, often having to prove this randomness as well. This includes security services for encryption purposes, but also private businesses. Online casinos, lottery draws and bingo games use True Random Number Generators, as it ensures that the winning numbers are trustworthy and impossible to tinker with.

Online bingo operators such as Buzz Bingo use these kinds of number generators as a way of recreating the fairness and unpredictability of a real-life game of bingo, making it impossible for anyone to fix or predict the numbers that result from a bingo draw. This is important both to players, who want to know they are playing a fair game, and to the authorities, who need to be aware of the legality of the processes. The same is true of sites that offer online slot games, or any other kind of gaming that relies on random numbers, not necessarily involving real bets.

They are also frequently used in simulations and modelling in order to help recreate real-world probabilities in simulations used for everything from car safety to computational drug testing. RNGs also have a number of applications within the arts, especially when it comes to randomised design pieces, some of which have made their way to the walls of famous art venues like the Saatchi Gallery.

The applications of random number generators are wide, and the future implications even wider. Understanding how they work is key to understanding just how useful the seemingly chaotic, random nature of the universe really is to us.