PHP rand（）与random_int（）

Question

As php.net indicates: random_int() function Generates cryptographically secure pseudo-random integers.

But, Can someone explain whats the difference between rand() & random_int()? Can I use random_int() instead of rand() when only requiring a random integer? Which one is faster?

Answer 1

Revisiting the question and seeing there's been an answer given, I find it's only fair that I submit my comments to an answer, seeing they were submitted before.

The manual on PHP 7's random_int() function states:

"Returns a cryptographically secure random integer in the range min to max, inclusive."

• http://php.net/manual/en/function.random-int.php

and for rand()

*This function does not generate cryptographically secure values" *

• http://php.net/manual/en/function.rand.php

OP's comment:

"@Fred-ii- thank you. But what does "cryptographically secure pseudo-random" mean? – NDFA"

That can be found in the following links as per my findings:

• https://en.wikipedia.org/wiki/Cryptographically_secure_pseudorandom_number_generator

Which states:

A cryptographically secure pseudo-random number generator (CSPRNG) or cryptographic pseudo-random number generator (CPRNG)[1] is a pseudo-random number generator (PRNG) with properties that make it suitable for use in cryptography.

---

• How does a cryptographically secure random number generator work?

In regards to performance, you will need to run a benchmark yourself.