Pseudo Random Number Generator(PRNG) refers to an algorithm that uses mathematical formulas to produce sequences of random numbers.

• PRNGs generate a sequence of numbers approximating the properties of random numbers.
• It is not possible to generate truly random numbers from deterministic thing like computers so PRNG is a technique developed to generate random numbers using a computer.

A PRNG starts from an arbitrary starting state using a seed state.

• Many numbers are generated in a short time and can also be reproduced later, if the starting point in the sequence is known.
• Hence, the numbers are deterministic and efficient.

Widely used PRNG algorithms include: Lagged Fibonacci generators, linear feedback shift registers, Blum Blum Shub.

• Efficient:
  • PRNG can produce many numbers in a short time and is advantageous for applications that need many numbers.
• Deterministic:
  • A given sequence of numbers can be reproduced at a later date if the starting point in the sequence is known.
  • Determinism is handy if you need to replay the same sequence of numbers again at a later stage.
• Periodic:
  • PRNGs are periodic, which means that the sequence will eventually repeat itself.
  • While periodicity is hardly ever a desirable characteristic, modern PRNGs have a period that is so long that it can be ignored for most practical purposes

PRNGs are suitable for applications where many random numbers are required and where it is useful that the same sequence can be replayed easily.

• Popular examples of such applications are simulation and modeling applications.
• PRNGs are not suitable for applications where it is important that the numbers are really unpredictable, such as data encryption and gambling.

A Pseudo Random Number Generator using srand()

Linear Congruential Generator

https://en.wikipedia.org/wiki/Linear_congruential_generator

https://www.pcg-random.org/index.html