Seeded, deterministic random number generator
Seeded, Deterministic PRNG (based on AES-CTR instead of LCG) (Requires PHP 7 or random_compat)
This is not meant to replace
random_bytes(). Think of this as an improvement
rand(). Do not use this for security purposes.
composer require paragonie/seedspring
use \ParagonIE\SeedSpring\SeedSpring; // For example $sharedSeed = str_repeat("\x80", 16); $rng = new SeedSpring($sharedSeed); $data = $rng->getBytes(1024); $int = $rng->getInt(1, 100);
A cryptographically secure pseudorandom number generator, such as
is wonderful for security purposes. However, there are situations where you need
to generate a deterministic, pseudorandom byte stream on two devices from a
shared seed. (e.g. something like Minecraft's world generator).
PHP's native seedable (and insecure) RNGs,
support a 32-bit integer seed, which severely limits the possible outputs. Our
deterministic RNG supports up to 2^128 possible outputs, since it's based on a
128-bit block cipher.
Our implementation uses AES-128-CTR to turn a finite, 128-bit key into an practically endless stream of random bytes. (It will repeat after 2^132 bytes of output. You should consider rekeying after 2^66 bytes.)