This package contains an implementation of a high-quality splittable pseudorandom number generator. The generator is based on a cryptographic hash function built on top of the ThreeFish block cipher. See the paper *Splittable Pseudorandom Number Generators Using Cryptographic Hashing* by Claessen, Pałka for details and the rationale of the design.

The package provides the following:

A splittable PRNG that implements the standard `System.Random.RandomGen`

class.

The generator also implements an alternative version of the `System.Random.TF.Gen.RandomGen`

class (exported from `System.Random.TF.Gen`

), which requires the generator to return pseudorandom integers from the full 32-bit range, and contains an n-way split function.

An alternative version of the `Random`

class is provided, which is linked to the new `RandomGen`

class, together with `Random`

instances for some integral types.

Two functions for initialising the generator with a non-deterministic seed: one using the system time, and one using the `/dev/urandom`

UNIX special file.

The package uses an adapted version of the reference C implementation of ThreeFish from the reference package of the Skein hash function (https://www.schneier.com/skein.html), originally written by Doug Whiting.

Please note that even though the generator provides very high-quality pseudorandom numbers, it has not been designed with cryptographic applications in mind.