Struct Transcript 

pub struct Transcript { /* private fields */ }

A Fiat-Shamir transcript.

Operations consume self and return a new transcript, ensuring the hash state evolves deterministically.

Examples

use field_cat::BabyBear;
use proof_cat_core::Transcript;

// Create a transcript, absorb some data, squeeze a challenge.
let transcript = Transcript::new(b"my-protocol")
    .absorb_field(&BabyBear::new(42));
let (_challenge, _transcript): (BabyBear, _) =
    transcript.squeeze_challenge()?;

// The challenge is deterministic: same inputs produce
// the same challenge every time.

Implementations

impl Transcript

pub fn new(label: &[u8]) -> Self

Create a new transcript with a domain separation label.

pub fn absorb_bytes(self, data: &[u8]) -> Self

Absorb raw bytes into the transcript.

pub fn absorb_field<F: FieldBytes>(self, elem: &F) -> Self

Absorb a field element into the transcript.

pub fn squeeze_challenge<F: FieldBytes>(self) -> Result<(F, Self), Error>

Squeeze a challenge field element from the transcript.

Hashes the current state with SHA-256, interprets the output as a field element, and returns the challenge along with an updated transcript.

Errors

Returns Error::FieldCat if the hash output cannot be interpreted as a field element.

Trait Implementations

impl Clone for Transcript

fn clone(&self) -> Transcript

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Transcript

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

Formats the value using the given formatter.