Struct Poseidon2SpongeState

pub struct Poseidon2SpongeState<F: PrimeField, const N: usize, const R: usize, P: Poseidon2Params<F, N>> { /* private fields */ }

the state of Poseidon2-based Cryptographic Sponge

Generic parameters:

• N: state size = rate (R) + capacity (C)
• R: rate (number of field absorbed/squeezed)

For security, for b=128-bit security, field size |F|, C*|F|>=2b: i.e. 128-bit for 256-bit fields, C>=1. This check is being down during Poseidon2SpongeState::new(&iv) (See Poseidon2 paper Page 7 Footnote 5)

For BLS12-381, we choose C=1 for 128 security For BN254, we choose C=1 for (100<*<128)-security

Trait Implementations

impl<F, const N: usize, const R: usize, P> AsMut<[F]> for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField, P: Poseidon2Params<F, N>,

fn as_mut(&mut self) -> &mut [F]

Converts this type into a mutable reference of the (usually inferred) input type.

impl<F, const N: usize, const R: usize, P> AsRef<[F]> for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField, P: Poseidon2Params<F, N>,

fn as_ref(&self) -> &[F]

Converts this type into a shared reference of the (usually inferred) input type.

impl<F: Clone + PrimeField, const N: usize, const R: usize, P: Clone + Poseidon2Params<F, N>> Clone for Poseidon2SpongeState<F, N, R, P>

fn clone(&self) -> Poseidon2SpongeState<F, N, R, P>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug + PrimeField, const N: usize, const R: usize, P: Debug + Poseidon2Params<F, N>> Debug for Poseidon2SpongeState<F, N, R, P>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<F, const N: usize, const R: usize, P> Default for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField, P: Poseidon2Params<F, N>,

fn default() -> Self

Returns the “default value” for a type.

impl<F, const N: usize, const R: usize, P> Sponge for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField + Unit, P: Poseidon2Params<F, N>,

const N: usize = N

The width of the sponge, equal to rate [Sponge::R] plus capacity. Cannot be less than 1. Cannot be less than [Sponge::R].

const R: usize = R

The rate of the sponge.

type U = F

The basic unit over which the sponge operates.

fn new(iv: [u8; 32]) -> Self

Initialize the state of the sponge using 32 bytes of seed.

fn permute(&mut self)

Permute the state of the sponge.

impl<F, const N: usize, const R: usize, P> Zeroize for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField, P: Poseidon2Params<F, N>,

fn zeroize(&mut self)

Zero out this object from memory using Rust intrinsics which ensure the zeroization operation is not “optimized away” by the compiler.

impl<F, const N: usize, const R: usize, P> Poseidon2Sponge for Poseidon2SpongeState<F, N, R, P>

where F: PrimeField, P: Poseidon2Params<F, N>,