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Add pending polishing on low-degree-testing impl

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arnaucube
2023-03-21 16:59:11 +01:00
parent cf20a56b0b
commit 1a58be7f83
3 changed files with 55 additions and 67 deletions
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5
Cargo.toml
View File

@@ -1,7 +1,10 @@
[package]
name = "fri-study"
name = "fri-commitment"
version = "0.1.0"
authors = ["arnaucube <root@arnaucube.com>"]
edition = "2021"
license = "GPL-3.0"
repository = "https://github.com/arnaucube/fri-commitment"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

112
src/lib.rs
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@@ -1,18 +1,21 @@
#![allow(non_snake_case)]
#![allow(non_camel_case_types)]
#![allow(non_upper_case_globals)]
pub mod merkletree;
use merkletree::{MerkleTreePoseidon as MT, Params as MTParams};
use merkletree::MerkleTreePoseidon as MT;
use ark_ff::PrimeField;
use ark_poly::{
univariate::DensePolynomial, EvaluationDomain, GeneralEvaluationDomain, UVPolynomial,
};
use ark_std::log2;
use ark_std::cfg_into_iter;
use ark_std::marker::PhantomData;
use ark_std::ops::Mul;
use ark_std::{cfg_into_iter, rand::Rng, UniformRand};
// rho^-1
const rho1: usize = 8; // WIP
pub struct FRI_LDT<F: PrimeField, P: UVPolynomial<F>> {
_f: PhantomData<F>,
@@ -46,7 +49,7 @@ impl<F: PrimeField, P: UVPolynomial<F>> FRI_LDT<F, P> {
}
// prove implements the proof generation for a FRI-low-degree-testing
pub fn prove<R: Rng>(rng: &mut R, p: &P) -> (Vec<F>, Vec<Vec<F>>, Vec<F>, [F; 2]) {
pub fn prove(p: &P) -> (Vec<F>, Vec<Vec<F>>, Vec<F>, [F; 2]) {
let d = p.degree();
let mut commitments: Vec<F> = Vec::new();
let mut mts: Vec<MT<F>> = Vec::new();
@@ -55,38 +58,25 @@ impl<F: PrimeField, P: UVPolynomial<F>> FRI_LDT<F, P> {
let mut f_i1 = p.clone();
// sub_order = |F_i| = rho^-1 * d
let mut sub_order = d; // TMP, TODO this will depend on rho parameter
let mut sub_order = d * rho1; // TMP, TODO this will depend on rho parameter
let mut eval_sub_domain: GeneralEvaluationDomain<F> =
GeneralEvaluationDomain::new(sub_order).unwrap();
// TODO merge in the next for loop
let evals: Vec<F> = cfg_into_iter!(0..eval_sub_domain.size())
.map(|k| f_i1.evaluate(&eval_sub_domain.element(k)))
.collect();
let (cm_i, mt_i) = MT::commit(&evals);
commitments.push(cm_i);
mts.push(mt_i);
sub_order = sub_order / 2;
eval_sub_domain = GeneralEvaluationDomain::new(sub_order).unwrap();
//
// V sets rand z \in \mathbb{F} challenge
// TODO this will be a hash from the transcript
let z_pos = 3;
let z = eval_sub_domain.element(z_pos);
let z_pos = z_pos * 2; // WIP
let mut f_is: Vec<P> = Vec::new();
f_is.push(p.clone());
while f_i1.degree() > 1 {
let alpha_i = F::from(42_u64); // TODO: WIP, defined by Verifier (well, hash transcript)
let (fL_i, fR_i) = Self::split(&f_i1);
// compute f_{i+1}(x) = fL_i(x) + alpha_i * fR_i(x)
let aux = DensePolynomial::from_coefficients_slice(fR_i.coeffs());
f_i1 = fL_i.clone() + P::from_coefficients_slice(aux.mul(alpha_i).coeffs());
// evals = {f_i(z^{2^i}), f_i(-z^{2^i})} \forall i \in F_i
let mut evals: Vec<F> = Vec::new();
let mut mtproofs: Vec<Vec<F>> = Vec::new();
let mut fL_i: P = P::from_coefficients_vec(Vec::new());
let mut fR_i: P = P::from_coefficients_vec(Vec::new());
let mut i = 0;
while f_i1.degree() >= 1 {
f_is.push(f_i1.clone());
let alpha_i = F::from(42_u64); // TODO: WIP, defined by Verifier (well, hash transcript)
let subdomain_evaluations: Vec<F> = cfg_into_iter!(0..eval_sub_domain.size())
.map(|k| f_i1.evaluate(&eval_sub_domain.element(k)))
@@ -97,31 +87,38 @@ impl<F: PrimeField, P: UVPolynomial<F>> FRI_LDT<F, P> {
commitments.push(cm_i);
mts.push(mt_i);
// prepare next subdomain
sub_order = sub_order / 2;
eval_sub_domain = GeneralEvaluationDomain::new(sub_order).unwrap();
}
let (fL_i, fR_i) = Self::split(&f_i1);
let constant_fL_l: F = fL_i.coeffs()[0].clone();
let constant_fR_l: F = fR_i.coeffs()[0].clone();
// evals = {f_i(z^{2^i}), f_i(-z^{2^i})} \forall i \in F_i
let mut evals: Vec<F> = Vec::new();
let mut mtproofs: Vec<Vec<F>> = Vec::new();
// TODO this will be done inside the prev loop, now it is here just for clarity
// evaluate f_i(z^{2^i}), f_i(-z^{2^i}), and open their commitment
for i in 0..f_is.len() {
// evaluate f_i(z^{2^i}), f_i(-z^{2^i}), and open their commitment
let z_2i = z.pow([2_u64.pow(i as u32)]); // z^{2^i} // TODO check usage of .pow(u64)
let neg_z_2i = z_2i.neg();
let eval_i = f_is[i].evaluate(&z_2i);
let eval_i = f_i1.evaluate(&z_2i);
evals.push(eval_i);
let eval_i = f_is[i].evaluate(&neg_z_2i);
let eval_i = f_i1.evaluate(&neg_z_2i);
evals.push(eval_i);
// gen the openings in the commitment to f_i(z^(2^i))
let mtproof = mts[i].open(F::from(z_pos as u32)); // WIP open to 2^i?
let mtproof = mts[i].open(F::from(z_pos as u32));
mtproofs.push(mtproof);
(fL_i, fR_i) = Self::split(&f_i1);
// compute f_{i+1}(x) = fL_i(x) + alpha_i * fR_i(x)
let aux = DensePolynomial::from_coefficients_slice(fR_i.coeffs());
f_i1 = fL_i.clone() + P::from_coefficients_slice(aux.mul(alpha_i).coeffs());
// prepare next subdomain
sub_order = sub_order / 2;
eval_sub_domain = GeneralEvaluationDomain::new(sub_order).unwrap();
i += 1;
}
if fL_i.coeffs().len() != 1 {
panic!("fL_i not constant");
}
if fR_i.coeffs().len() != 1 {
panic!("fR_i not constant");
}
let constant_fL_l: F = fL_i.coeffs()[0].clone();
let constant_fR_l: F = fR_i.coeffs()[0].clone();
(commitments, mtproofs, evals, [constant_fL_l, constant_fR_l])
}
@@ -134,13 +131,12 @@ impl<F: PrimeField, P: UVPolynomial<F>> FRI_LDT<F, P> {
evals: Vec<F>,
constants: [F; 2],
) -> bool {
let sub_order = ((degree + 1) / 2) - 1; // TMP, TODO this will depend on rho parameter
let sub_order = rho1 * degree; // TMP, TODO this will depend on rho parameter
let eval_sub_domain: GeneralEvaluationDomain<F> =
GeneralEvaluationDomain::new(sub_order).unwrap();
// TODO this will be a hash from the transcript
let z_pos = 3;
let z = eval_sub_domain.element(z_pos);
let z_pos = z_pos * 2;
if commitments.len() != (evals.len() / 2) {
println!("sho commitments.len() != (evals.len() / 2) - 1");
@@ -176,7 +172,6 @@ impl<F: PrimeField, P: UVPolynomial<F>> FRI_LDT<F, P> {
// check commitment opening
if !MT::verify(
commitments[i_z],
// F::from(i as u32),
F::from(z_pos as u32),
evals[i],
mtproofs[i_z].clone(),
@@ -209,9 +204,11 @@ mod tests {
use super::*;
use ark_ff::Field;
use ark_std::UniformRand;
pub type Fr = ark_bn254::Fr; // scalar field
// pub type Fr = ark_bn254::Fr; // scalar field
use ark_bn254::Fr; // scalar field
use ark_poly::univariate::DensePolynomial;
use ark_poly::Polynomial;
use ark_std::log2;
#[test]
fn test_split() {
@@ -220,8 +217,8 @@ mod tests {
let p = DensePolynomial::<Fr>::rand(deg, &mut rng);
assert_eq!(p.degree(), deg);
type FRIT = FRI_LDT<Fr, DensePolynomial<Fr>>;
let (pL, pR) = FRIT::split(&p);
type FRID = FRI_LDT<Fr, DensePolynomial<Fr>>;
let (pL, pR) = FRID::split(&p);
// check that f(z) == fL(x^2) + x * fR(x^2), for a rand z
let z = Fr::rand(&mut rng);
@@ -235,26 +232,19 @@ mod tests {
fn test_prove() {
let mut rng = ark_std::test_rng();
let deg = 15;
let deg = 31;
let p = DensePolynomial::<Fr>::rand(deg, &mut rng);
assert_eq!(p.degree(), deg);
// println!("p {:?}", p);
type FRIT = FRI_LDT<Fr, DensePolynomial<Fr>>;
// prover
let (commitments, mtproofs, evals, constvals) = FRIT::prove(&mut rng, &p);
type FRID = FRI_LDT<Fr, DensePolynomial<Fr>>;
let (commitments, mtproofs, evals, constvals) = FRID::prove(&p);
// commitments contains the commitments to each f_0, f_1, ..., f_n, with n=log2(d)
assert_eq!(commitments.len(), log2(p.coeffs().len()) as usize);
assert_eq!(evals.len(), 2 * log2(p.coeffs().len()) as usize);
let v = FRIT::verify(
// Fr::from(deg as u32),
deg,
commitments,
mtproofs,
evals,
constvals,
);
let v = FRID::verify(deg, commitments, mtproofs, evals, constvals);
assert!(v);
}
}

5
src/merkletree.rs
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@@ -151,11 +151,6 @@ impl<F: PrimeField> MerkleTree<F> {
pub struct MerkleTreePoseidon<F: PrimeField>(MerkleTree<F>);
pub struct MTProof<F: PrimeField> {
index: F,
siblings: Vec<F>,
}
impl<F: PrimeField> MerkleTreePoseidon<F> {
pub fn commit(values: &[F]) -> (F, Self) {
let poseidon_params = poseidon_setup_params::<F>(Curve::Bn254, 5, 4);