shared_types/transcript/
keccak_transcript.rs

1use itertools::Itertools;
2use sha3::{Digest, Keccak512};
3
4use crate::Field;
5
6use super::TranscriptSponge;
7
8#[derive(Clone, Debug, Default)]
9pub struct KeccakTranscript {
10    hasher: Keccak512,
11}
12
13impl<F> TranscriptSponge<F> for KeccakTranscript
14where
15    F: Field<Repr = [u8; 32]>,
16{
17    fn absorb(&mut self, elem: F) {
18        self.hasher.update(elem.to_repr())
19    }
20
21    fn absorb_elements(&mut self, elements: &[F]) {
22        let bytes = elements.iter().flat_map(F::to_repr).collect_vec();
23        self.hasher.update(&bytes)
24    }
25
26    fn squeeze(&mut self) -> F {
27        let out = self.hasher.finalize_reset();
28        self.hasher.update(out);
29
30        F::from_uniform_bytes(out.as_slice().try_into().unwrap())
31    }
32
33    fn squeeze_elements(&mut self, num_elements: usize) -> Vec<F> {
34        (0..num_elements)
35            .map(|_| {
36                let out = self.hasher.finalize_reset();
37                self.hasher.update(out);
38
39                F::from_uniform_bytes(out.as_slice().try_into().unwrap())
40            })
41            .collect_vec()
42    }
43
44    fn absorb_initialization_label(&mut self, label: &str) {
45        let label_as_bytes = label.as_bytes();
46        let label_as_field_elems = F::vec_from_bytes_le(label_as_bytes);
47        self.absorb_elements(&label_as_field_elems);
48    }
49}
50
51#[cfg(test)]
52mod tests {
53    use halo2curves::bn256::Fq;
54
55    use crate::transcript::{
56        ec_transcript::{ECTranscript, ECTranscriptTrait},
57        ProverTranscript,
58    };
59
60    use super::KeccakTranscript;
61
62    #[test]
63    fn test_keccak() {
64        let mut transcript =
65            ECTranscript::<halo2curves::bn256::G1, KeccakTranscript>::new("new transcript");
66        transcript.append("test2", Fq::one());
67        let one = halo2curves::bn256::G1::generator();
68        transcript.append_ec_point("ec_test", one);
69        let _: Fq = transcript.get_challenge("test_challenge_2");
70    }
71}
shared_types/transcript/keccak_transcript.rs

shared_types/transcript/
keccak_transcript.rs
