Module rand_chacha 

ChaCha-based cryptographically secure random number generators.

• Crate ::rand_chacha.
• docs.rs
• crates.io
• GitHub

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rand_chacha provides random number generators based on the ChaCha stream cipher. These are cryptographically secure and portable – given the same seed they produce identical output on all platforms.

Three variants are available, differing in the number of ChaCha rounds:

• ChaCha20Rng – 20 rounds, the standard choice for cryptographic security.
• ChaCha12Rng – 12 rounds, a good default balancing security and speed.
• ChaCha8Rng – 8 rounds, fastest but with a lower security margin.

If you neeed a specific, stable, secure random number generator pick ChaCha12 by default.

ChaCha20 is tha standard strength algorithm and considered secure. ChaCha12 is weaker, but expert consensus is that it is also secure, with no known attacks (it is the the default algorithm of the rand crate’s StdRng, though its algorithm is not specified to be stable).

Example

use rand::SeedableRng;
use rand::RngExt;
use rand_chacha::ChaCha12Rng;

let mut rng = ChaCha12Rng::seed_from_u64(42);

let value: u32 = rng.random();
let in_range: f64 = rng.random_range(0.0..1.0);
let coin: bool = rng.random();

Modules

rand_core

Structs

ChaCha8Core

ChaCha with 8 rounds

ChaCha8Rng

A cryptographically secure random number generator that uses the ChaCha algorithm.

ChaCha12Core

ChaCha with 12 rounds

ChaCha12Rng

A cryptographically secure random number generator that uses the ChaCha algorithm.

ChaCha20Core

ChaCha with 20 rounds

ChaCha20Rng

A cryptographically secure random number generator that uses the ChaCha algorithm.

Type Aliases

ChaChaCore

ChaCha with 20 rounds, low-level interface

ChaChaRng

ChaCha with 20 rounds