PRNG

Collection of pseudorandom number generators. And also the tools for them.

List of PRNG's

32 bits:

• xorshift32
• xorshift128
• xorwow
• xoroshiro64(*/**)
• xoshiro128(+/++/**)
• mt19937
• splitmix32
• pcg32
• lfsr32
• jsf32
• well512a
• msws32

64 bits:

• xorshift64[*]
• xorshift[r]128+
• xoshiro256(+/++/**)
• xoshiro512(+/++/**)
• xoroshiro128(+/++/**)
• xoroshiro1024(++/*/**)
• mt19937-64
• splitmix64
• pcg64
• lfsr64
• lfsr128
• jsf64
• msws64
• siprand

All generators output number in range $[0; 2^w)$, where $w$ is output bit width.

Basic API

prng_xxx_state_t - structure of storage generator inner state
prng_xxx_ret_t - generator output integer type
prng_xxx_seed - set state of generator from passed seed
prng_xxx_gen - return pseudorandom integer
where xxx - name of prng.

PRNG_ENGINE - name of generator by default, if not defined then equal xoshiro256ss
use for macros: prng_state_t, prng_ret_t, prng_seed, prng_gen.

Extentions

All extentions is single header. If has functions you maybe preinclude define PRNGE_XXX_IMPLEMENTATION for add definitions of functions.

Engine

Simple structure for storage generator function and pointer to state for him. Using in uniform distribution.

Uniform distributions

uidistr - uniform integer distribution. Convert range $[0; 2^w)$ to $[min; max]$, where $w$ is 32 or 64
ufdistr - uniform float distribution. Convert range $[0; 2^{32})$* to $[0; 1)$
uddistr - uniform double distribution. Convert range $[0; 2^{64})$** to $[0; 1)$
* - use higher 24 bit from integer
** - use higher 53 bit from integer

Seed sequence

Taken from: pcg alternative of std::seed_seq

Structure prnge_seedseq_t use for mixing start entropy and filling prng state at 'seed' values.

Simple exapmle

prnge_seedseq_t sq;
// fill sequence outer entropy
prnge_seedseq_init(&sq, (uint32_t[4]){time(0), clock(), 0, 0});
/* ... */
uint32_t state[4] = {0};
prnge_seedseq_get_u32(&sq, state, 4); // set state at seeds

My stuffs

SipRand

This generator based on SipRound function from SipHash function. For result use reduced XOR state[0..3]

Xoshiro256** secret messages

Taken from: pcg blog about xoshiro256**

How get message:

1. Set state with magic values
2. Get from current state 256 bytes (32 x 64-bit integers)
3. Open this 256 bytes in hex reader
4. On address 0x80 start secret message

Magic states:

1. Author signature - { 0x01d353e5f3993bb0, 0x7b9c0df6cb193b20, 0xfdfcaa91110765b6, 0xd2db341f10bb232e }
2. "Please don't multiply by 57" - { 0x4685307f2e2c9b43, 0xa999f3abba9e66fe, 0xf74ff5fab0e603da, 0x6dc878990b1ea4db }