Struct PoseidonSponge 

pub struct PoseidonSponge(/* private fields */);

Poseidon sponge in the absorb phase (before padding).

Call Self::finish_absorbing when all input has been absorbed to obtain a PoseidonSpongeSqueeze. Further absorption is rejected by the type system: the sponge state after padding is not a valid absorb continuation.

Implementations

impl PoseidonSponge

pub fn new(params: PoseidonParams) -> Self

Create a new Poseidon sponge with the given parameters

pub fn absorb(&mut self, elements: &[PoseidonField])

Absorb field elements into the sponge

Arguments

• elements - Field elements to absorb

pub fn finish_absorbing(self) -> PoseidonSpongeSqueeze

Finish absorbing and apply padding (10*1 in rate only)

Should be called after all input has been absorbed. Returns a value that only supports PoseidonSpongeSqueeze::squeeze, so additional PoseidonSponge::absorb calls are impossible after padding (they would define a non-standard sponge).

Standard sponge padding: add 1 at state[absorbed]; if that does not fill the rate block (absorbed + 1 < rate), add 1 at state[rate - 1] to distinguish single-block from multi-block inputs. Capacity is not written.

Compile-time safety

After this call, PoseidonSponge is consumed; PoseidonSpongeSqueeze has no absorb, so further input cannot be appended after padding:

use lib_q_poseidon::{Poseidon128, PoseidonSponge};
let params = Poseidon128::params();
let sponge = PoseidonSponge::new(params);
let mut sponge = sponge.finish_absorbing();
sponge.absorb(&[]);

pub fn finalize(self) -> Vec<PoseidonField>

Finalize the sponge (apply padding and final permutation)

Convenience for callers that need the full width state after padding without squeezing. Otherwise use Self::finish_absorbing followed by PoseidonSpongeSqueeze::squeeze.

pub fn capacity(&self) -> usize

Get the capacity value

pub fn rate(&self) -> usize

Get the rate value

Trait Implementations

impl Clone for PoseidonSponge

fn clone(&self) -> PoseidonSponge

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PoseidonSponge

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

Formats the value using the given formatter.