[][src]Struct rand_isaac::isaac64::Isaac64Rng

pub struct Isaac64Rng(_);

A random number generator that uses ISAAC-64, the 64-bit variant of the ISAAC algorithm.

ISAAC stands for "Indirection, Shift, Accumulate, Add, and Count" which are the principal bitwise operations employed. It is the most advanced of a series of array based random number generator designed by Robert Jenkins in 19961.

ISAAC-64 is mostly similar to ISAAC. Because it operates on 64-bit integers instead of 32-bit, it uses twice as much memory to hold its state and results. Also it uses different constants for shifts and indirect indexing, optimized to give good results for 64bit arithmetic.

ISAAC-64 is notably fast and produces excellent quality random numbers for non-cryptographic applications.

In spite of being designed with cryptographic security in mind, ISAAC hasn't been stringently cryptanalyzed and thus cryptographers do not not consensually trust it to be secure. When looking for a secure RNG, prefer Hc128Rng from the rand_hc crate instead, which, like ISAAC, is an array-based RNG and one of the stream-ciphers selected the by eSTREAM

Overview of the ISAAC-64 algorithm:

(in pseudo-code)

Input: a, b, c, s[256] // state
Output: r[256] // results

mix(a,i) = !(a ^ a << 21)  if i = 0 mod 4
             a ^ a >>  5   if i = 1 mod 4
             a ^ a << 12   if i = 2 mod 4
             a ^ a >> 33   if i = 3 mod 4

c = c + 1
b = b + c

for i in 0..256 {
    x = s_[i]
    a = mix(a,i) + s[i+128 mod 256]
    y = a + b + s[x>>3 mod 256]
    s[i] = y
    b = x + s[y>>11 mod 256]
    r[i] = b
}

This implementation uses BlockRng64 to implement the RngCore methods.

See for more information the documentation of IsaacRng.


  1. Bob Jenkins, ISAAC and RC4 

Trait Implementations

impl Debug for Isaac64Rng[src]

impl Clone for Isaac64Rng[src]

fn clone_from(&mut self, source: &Self)1.0.0[src]

Performs copy-assignment from source. Read more

impl Serialize for Isaac64Rng[src]

impl<'de> Deserialize<'de> for Isaac64Rng[src]

impl RngCore for Isaac64Rng[src]

impl SeedableRng for Isaac64Rng[src]

type Seed = <Isaac64Core as SeedableRng>::Seed

Seed type, which is restricted to types mutably-dereferencable as u8 arrays (we recommend [u8; N] for some N). Read more

fn seed_from_u64(seed: u64) -> Self[src]

Create an ISAAC random number generator using an u64 as seed. If seed == 0 this will produce the same stream of random numbers as the reference implementation when used unseeded.

fn from_entropy() -> Self[src]

Creates a new instance of the RNG seeded via [getrandom]. Read more

Auto Trait Implementations

impl Send for Isaac64Rng

impl Sync for Isaac64Rng

impl Unpin for Isaac64Rng

impl UnwindSafe for Isaac64Rng

impl RefUnwindSafe for Isaac64Rng

Blanket Implementations

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
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type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> Into<U> for T where
    U: From<T>, 
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impl<T> From<T> for T[src]

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<T> Borrow<T> for T where
    T: ?Sized
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impl<T> BorrowMut<T> for T where
    T: ?Sized
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impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> ToOwned for T where
    T: Clone
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type Owned = T

The resulting type after obtaining ownership.

impl<T> DeserializeOwned for T where
    T: Deserialize<'de>, 
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