# Pseudo-random number generator (PRNG)

A pseudo-random number generator (PRNG) is a computer program that generates a sequence of numbers that looks like a random sequence, but is actually deterministic. A PRNG is seeded with an initial value, called the seed, and then generates a sequence of numbers from that seed. If the same seed is used twice, the same sequence of numbers will be generated.

PRNGs are used in many applications, including Monte Carlo simulations, computer games, and cryptography. They are also used to generate random numbers for lotteries and giveaways.

There are many different algorithms that can be used to create a PRNG. Some of the more popular ones include the Linear Congruential Generator (LCG), the Mersenne Twister, and the Blum Blum Shub.

PRNGs are not truly random because they are deterministic. However, they are designed to generate numbers that are statistically indistinguishable from true random numbers.

##### What is meant by a cryptographically strong pseudo random number generator PRNG )?

A cryptographically strong pseudo random number generator (PRNG) is a pseudo random number generator that is resistant to cryptographic attacks.

There are two types of cryptographic attacks that a PRNG must be resistant to:

1. Static attacks: These are attacks where the attacker knows the algorithm used to generate the pseudo random numbers, and has access to a large number of the pseudo random numbers that have been generated.

2. Dynamic attacks: These are attacks where the attacker does not know the algorithm used to generate the pseudo random numbers, but has access to some of the pseudo random numbers that have been generated.

To be resistant to static attacks, a PRNG must use an algorithm that is not known to the attacker. To be resistant to dynamic attacks, a PRNG must use an algorithm that is not predictable.

A PRNG is considered to be cryptographically strong if it is resistant to both types of attacks.

##### What are pseudo random number generator used for?

Pseudo random number generators are used in a variety of applications, such as:

- Generating random numbers for use in simulations
- Generating random numbers for use in games
- Generating random numbers for use in cryptographic applications

### Can you predict PRNG?

The answer to this question is both yes and no. While it is possible to predict the output of a pseudorandom number generator (PRNG) if you know the algorithm and seed used, it is also possible to design PRNGs that are difficult or impossible to predict.

If you know the algorithm used to generate the pseudorandom numbers, as well as the seed value, then it is possible to predict the output of the PRNG. This is because the algorithm will always produce the same output given the same seed value. However, if you do not know the algorithm or seed value, then it may be difficult or impossible to predict the output of the PRNG.

There are a number of different algorithms that can be used to generate pseudorandom numbers, and each one will produce a different output given the same seed value. Some of these algorithms are more difficult to predict than others. For example, the Linear Congruential Generator (LCG) is a relatively simple algorithm that is easy to predict if you know the seed value. However, more complex algorithms such as the Mersenne Twister are much more difficult to predict, even if you know the seed value.

In general, it is difficult to predict the output of a PRNG if you do not know the algorithm or seed value. However, there are some methods that can be used to attack PRNGs, such as the birthday attack. This attack is based on the fact What generates pseudorandom integer? There is no definitive answer to this question as there are many different ways to generate pseudorandom integers. Some common methods include using a linear congruential generator, a Mersenne Twister, or a Xorshift.

#### Which are requirements of PRNG?

A pseudorandom number generator (PRNG) is an algorithm that produces sequences of pseudorandom numbers. Pseudorandom numbers are not truly random, but they are close enough to random for most purposes.

There are several requirements that a PRNG must meet in order to be considered good:

1. The algorithm must be deterministic. This means that if you know the seed (the starting value) and the algorithm, you can predict the next number in the sequence.

2. The algorithm must beperiodic. This means that the sequence of numbers will eventually repeat itself.

3. The algorithm must beuniform. This means that each number in the sequence is equally likely to be generated.

4. The algorithm must beefficient. This means that it can generate a large number of pseudorandom numbers quickly.