Struct TranscriptWriter 

pub struct TranscriptWriter<F, T> {
    sponge: T,
    transcript: Transcript<F>,
}

The prover-side interface for interacting with a transcript sponge. A TranscriptWriter acts as a wrapper around a TranscriptSponge and additionally keeps track of all the append/squeeze operations to be able to generate a serializable Transcript.

Fields

sponge: T

The sponge that this writer is using to append/squeeze elements.

transcript: Transcript<F>

A mutable transcript which keeps a record of all the append/squeeze operations.

Implementations

impl<F: Field, Tr: TranscriptSponge<F>> TranscriptWriter<F, Tr>

pub fn get_transcript(self) -> Transcript<F>

Destructively extract the transcript produced by this writer. This should be the last operation performed on a TranscriptWriter.

pub fn new(label: &str) -> Self

Creates an empty sponge. label is an identifier and will be absorbed into the transcript upon intialization.

Trait Implementations

impl<F: Field, Tr: TranscriptSponge<F>> ProverTranscript<F> for TranscriptWriter<F, Tr>

fn append(&mut self, label: &str, elem: F)

Append an element to the sponge and record the operation to the transcript. label is an identifier for this operation and is used for sanity checking by the TranscriptReader.

fn append_elements(&mut self, label: &str, elements: &[F])

Append a slice of elements to the sponge sequentially and record the operation on the transcript. If elements is the empty slice, the operation is not recorded. label is an identifier for this operation and is used for sanity checking by the TranscriptReader.

fn get_challenge(&mut self, label: &str) -> F

Squeezes the sponge once to get an element and records the squeeze operation on the transcript. label serves as sanity-check identifier by the TranscriptReader.

fn get_challenges(&mut self, label: &str, num_elements: usize) -> Vec<F>

Squeezes the sponge num_elements times to get a sequence of elements and records the operation on the transcript. If num_elements == 0, the empty vector is returned and the operation is not recorded on the transcript. label serves as sanity-check identifier by the TranscriptReader.

fn append_input_elements(&mut self, label: &str, elements: &[F])

A function which MUST be used on circuit inputs as an additional deterrant against the attack specified in https://eprint.iacr.org/2025/118, by absorbing H(H(H(…H(x)…))) into the Transcript, where x is a circuit input and H is the hash function defined in the below field.