What is a random number generator?

A random number generator, or RNG, is a mathematical tool used to generate a sequence of numbers that have no discernible pattern. Random number generators are commonly used to create games of chance, such as slot machines and lottery drawings. However, they also have practical applications in computer science, physics, cryptography and more.

Essentially, a random number generator works by creating seemingly unconnected numbers. A variety of algorithms are used to ensure that the numbers are truly random and cannot be predicted or affected by the most recent number generated. However, the output from an RNG may appear to be non-random if there is not enough "entropy," which is basically a measure of the unpredictability of a system.

One popular example of a random number generator algorithm is known as the "Mersenne Twister." Developed in 1997 by Makoto Matsumoto and Takuji Nishimura at Nagoya University in Japan, it has become an industry standard because it generates extremely chaotic numbers with good uniformity — meaning that the probability any two given numbers will appear is equal or close to equal. This makes it well-suited for applications that require computer-generated randomness like simulation modeling or cryptography.

Random number generators are vital parts of everyday consumer technology like smartphone encryption applications or online security protocols. They're also important components for gaming systems like PlayStation consoles as well as digital currency miners since they can "mine" new currencies from data blocks using "hashes" created by complex mathematical equations that require chaotic input from RNGs.

Since random number generators can be vital for such wide range of tasks, scientists have created extensive tests to ensure their accuracy and reliability — such as using the National Institute for Standards and Technology's "TestU01" toolkit which consists over 700 tests designed to measure an RNG's suitability for specific tasks like simulations or scientific experiments.