bkmgit / shishua

SHISHUA – The fastest PRNG in the world

SHISHUA – The Fastest PRNG In The World

The announcement and explanation blog post is here.

Note: please do not use this for cryptographic purposes. If you need security, a recommended option is ChaCha20.

Implementations:

• C
• Rust
• Node.js (on npm)
• Python (on PyPI)

Comparison

Name	Intel Performance	ARM Performance	Quality	Seed correlation
SHISHUA	52.93 GB/s	8.78 GB/s	>32 TiB	>32 TiB
xoshiro256+x8	40.18 GB/s	3.69 GB/s	1 KiB	0 KiB
RomuTrio	8.62 GB/s	4.76 GB/s	>32 TiB	1 KiB
xoshiro256+	7.88 GB/s	4.31 GB/s	512 MiB	1 KiB
wyrand	7.00 GB/s	2.53 GB/s	>32 TiB	32 KiB
Lehmer128	6.14 GB/s	1.83 GB/s	>32 TiB	1 KiB
ChaCha8	6.28 GB/s	1.72 GB/s	>32 TiB?	>32 TiB?
RC4	0.35 GB/s	0.15 GB/s	1 TiB	1 KiB

1. Performance: in number of CPU cycles spent per byte generated, on N2 GCP instances. On N2D (AMD), the order is the same.
2. Quality: level at which it fails PractRand. We show a > if it did not fail. We put a question mark if we have not proved it.
3. Seed correlation: PractRand on interleaving of bytes from eight streams with seeds 1, 2, 4, 8, 16, 32, 64, 128. We use PractRand with folding 2 and expanded tests.

On the subject of seed correlations, the ./bin/sample-seed-fingerprints.sh program highlights additional anomalies:

• RC4 has weak seeds with heavy artefacts visible in the fingerprints.
• RomuTrio's fingerprints start with the same first character for all seeds.

Commands

• make: build ./shishua.
• make test: run performance tests, PractRand, and BigCrush on SHISHUA.
• make test/benchmark-seed: run seed correlation test.
• make test/benchmark-perf: run performance comparison locally.
• make benchmark-intel: run performance comparison on a GCP Intel chip.
• make benchmark-amd: run performance comparison on a GCP AMD chip.
• make benchmark-arm: run performance comparison on an AWS Graviton ARM chip.

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The SHISHUA and SHISHUA-half are under the CC0 license.