impl zero check (#15) and vp operations (#17)

This commit is contained in:
zhenfei
2022-05-16 11:48:19 -04:00
committed by GitHub
parent 0b251a38e8
commit 0d77c3a2b1
10 changed files with 511 additions and 462 deletions

View File

@@ -1,11 +1,7 @@
mod prover;
mod verifier;
use ark_ff::PrimeField;
use ark_poly::DenseMultilinearExtension;
pub use prover::ProverState;
use ark_std::{end_timer, start_timer};
use std::rc::Rc;
pub use verifier::VerifierState;
use crate::{
errors::PolyIOPErrors,
@@ -31,6 +27,8 @@ pub trait ZeroCheck<F: PrimeField> {
/// ZeroCheck prover/verifier.
fn init_transcript() -> Self::Transcript;
/// initialize the prover to argue for the sum of polynomial over
/// {0,1}^`num_vars` is zero.
fn prove(
poly: &Self::PolyList,
transcript: &mut Self::Transcript,
@@ -48,7 +46,11 @@ impl<F: PrimeField> ZeroCheck<F> for PolyIOP<F> {
type Proof = IOPProof<F>;
type PolyList = VirtualPolynomial<F>;
type DomainInfo = DomainInfo<F>;
type SubClaim = SubClaim<F>;
/// A ZeroCheck SubClaim consists of
/// - the SubClaim from the ZeroCheck
/// - the initial challenge r which is used to build eq(x, r)
type SubClaim = (SubClaim<F>, Vec<F>);
type Transcript = IOPTranscript<F>;
/// Initialize the system with a transcript
@@ -61,29 +63,53 @@ impl<F: PrimeField> ZeroCheck<F> for PolyIOP<F> {
IOPTranscript::<F>::new(b"Initializing ZeroCheck transcript")
}
/// initialize the prover to argue for the sum of polynomial over
/// {0,1}^`num_vars` is zero.
fn prove(
poly: &Self::PolyList,
transcript: &mut Self::Transcript,
) -> Result<Self::Proof, PolyIOPErrors> {
let start = start_timer!(|| "zero check prove");
let length = poly.domain_info.num_variables;
let r = transcript.get_and_append_challenge_vectors(b"vector r", length)?;
let f_hat = build_f_hat(poly, r.as_ref());
<Self as SumCheck<F>>::prove(&f_hat, transcript)
let f_hat = build_f_hat(poly, r.as_ref())?;
let res = <Self as SumCheck<F>>::prove(&f_hat, transcript);
end_timer!(start);
res
}
/// Verify the claimed sum using the proof.
/// Caller needs to makes sure that `\hat f = f * eq(x, r)`
/// the initial challenge `r` is also returned.
/// The caller needs to makes sure that `\hat f = f * eq(x, r)`
fn verify(
proof: &Self::Proof,
domain_info: &Self::DomainInfo,
fx_domain_info: &Self::DomainInfo,
transcript: &mut Self::Transcript,
) -> Result<Self::SubClaim, PolyIOPErrors> {
println!(
"sum: {}",
proof.proofs[0].evaluations[0] + proof.proofs[0].evaluations[1]
);
let start = start_timer!(|| "zero check verify");
<Self as SumCheck<F>>::verify(F::zero(), proof, domain_info, transcript)
// check that the sum is zero
if proof.proofs[0].evaluations[0] + proof.proofs[0].evaluations[1] != F::zero() {
return Err(PolyIOPErrors::InvalidProof(format!(
"zero check: sum {} is not zero",
proof.proofs[0].evaluations[0] + proof.proofs[0].evaluations[1]
)));
}
// generate `r` and pass it to the caller for correctness check
let length = fx_domain_info.num_variables;
let r = transcript.get_and_append_challenge_vectors(b"vector r", length)?;
// hat_fx's max degree is increased by eq(x, r).degree() which is 1
let mut hat_fx_domain_info = fx_domain_info.clone();
hat_fx_domain_info.max_degree += 1;
let subclaim =
<Self as SumCheck<F>>::verify(F::zero(), proof, &hat_fx_domain_info, transcript)?;
end_timer!(start);
Ok((subclaim, r))
}
}
@@ -91,39 +117,20 @@ impl<F: PrimeField> ZeroCheck<F> for PolyIOP<F> {
// \hat f(x) = \sum_{x_i \in eval_x} f(x_i) eq(x, r)
// where
// eq(x,y) = \prod_i=1^num_var (x_i * y_i + (1-x_i)*(1-y_i))
fn build_f_hat<F: PrimeField>(poly: &VirtualPolynomial<F>, r: &[F]) -> VirtualPolynomial<F> {
fn build_f_hat<F: PrimeField>(
poly: &VirtualPolynomial<F>,
r: &[F],
) -> Result<VirtualPolynomial<F>, PolyIOPErrors> {
let start = start_timer!(|| "zero check build hat f");
assert_eq!(poly.domain_info.num_variables, r.len());
let mut res = poly.clone();
let eq_x_r = build_eq_x_r(r);
res.add_product([eq_x_r; 1], F::one());
// // First, we build array for {1 - r_i}
// let one_minus_r: Vec<F> = r.iter().map(|ri| F::one() - ri).collect();
let mut res = poly.clone();
res.mul_by_mle(eq_x_r, F::one())?;
// let mut eval = vec![];
// // let eq_x_r = build_eq_x_r(r);
// let num_var = r.len();
// let mut res = VirtualPolynomial::new(num_var);
// // res.add_product([eq_x_r; 1], F::one());
// for i in 0..1 << num_var {
// let bit_sequence = bit_decompose(i, num_var);
// let bit_points: Vec<F> = bit_sequence.iter().map(|&x| F::from(x as
// u64)).collect(); let mut eq_eval = F::one();
// for (&bit, (ri, one_minus_ri)) in
// bit_sequence.iter().zip(r.iter().zip(one_minus_r.iter())) {
// if bit {
// eq_eval *= ri;
// } else {
// eq_eval *= one_minus_ri;
// }
// }
// eval.push(eq_eval * poly.evaluate(&bit_points))
// }
// let hat_f = Rc::new(DenseMultilinearExtension::from_evaluations_vec(
// num_var, eval,
// ));
// res.add_product([hat_f; 1], F::one());
res
end_timer!(start);
Ok(res)
}
// Evaluate
@@ -131,6 +138,8 @@ fn build_f_hat<F: PrimeField>(poly: &VirtualPolynomial<F>, r: &[F]) -> VirtualPo
// over r, which is
// eq(x,y) = \prod_i=1^num_var (x_i * r_i + (1-x_i)*(1-r_i))
fn build_eq_x_r<F: PrimeField>(r: &[F]) -> Rc<DenseMultilinearExtension<F>> {
let start = start_timer!(|| "zero check build build eq_x_r");
// we build eq(x,r) from its evaluations
// we want to evaluate eq(x,r) over x \in {0, 1}^num_vars
// for example, with num_vars = 4, x is a binary vector of 4, then
@@ -157,18 +166,14 @@ fn build_eq_x_r<F: PrimeField>(r: &[F]) -> Rc<DenseMultilinearExtension<F>> {
for (&bit, (ri, one_minus_ri)) in bit_sequence.iter().zip(r.iter().zip(one_minus_r.iter()))
{
if bit {
current_eval *= *ri;
} else {
current_eval *= *one_minus_ri;
}
current_eval *= if bit { *ri } else { *one_minus_ri };
}
eval.push(current_eval);
}
let res = Rc::new(DenseMultilinearExtension::from_evaluations_vec(
num_var, eval,
));
let mle = DenseMultilinearExtension::from_evaluations_vec(num_var, eval);
let res = Rc::new(mle);
end_timer!(start);
res
}
@@ -186,131 +191,83 @@ fn bit_decompose(input: u64, num_var: usize) -> Vec<bool> {
mod test {
use super::ZeroCheck;
use crate::{virtual_poly::test::random_zero_list_of_products, PolyIOP, VirtualPolynomial};
use crate::{errors::PolyIOPErrors, PolyIOP, VirtualPolynomial};
use ark_bls12_381::Fr;
use ark_ff::UniformRand;
use ark_poly::{DenseMultilinearExtension, MultilinearExtension};
use ark_std::test_rng;
use std::rc::Rc;
fn test_polynomial(nv: usize, num_multiplicands_range: (usize, usize), num_products: usize) {
fn test_zerocheck(
nv: usize,
num_multiplicands_range: (usize, usize),
num_products: usize,
) -> Result<(), PolyIOPErrors> {
let mut rng = test_rng();
let mut transcript = PolyIOP::init_transcript();
transcript
.append_message(b"testing", b"initializing transcript for testing")
.unwrap();
let poly = random_zero_list_of_products::<Fr, _>(
nv,
num_multiplicands_range,
num_products,
&mut rng,
);
// println!("{:?}", poly);
let proof = PolyIOP::prove(&poly, &mut transcript).expect("fail to prove");
println!(
"{}",
proof.proofs[0].evaluations[0] + proof.proofs[0].evaluations[1]
);
{
// good path: zero virtual poly
let poly =
VirtualPolynomial::rand_zero(nv, num_multiplicands_range, num_products, &mut rng)?;
let poly_info = poly.domain_info.clone();
let mut transcript = PolyIOP::init_transcript();
transcript
.append_message(b"testing", b"initializing transcript for testing")
.unwrap();
let subclaim =
PolyIOP::verify(&proof, &poly_info, &mut transcript).expect("fail to verify");
assert!(
poly.evaluate(&subclaim.point) == subclaim.expected_evaluation,
"wrong subclaim"
);
let mut transcript = <PolyIOP<Fr> as ZeroCheck<Fr>>::init_transcript();
transcript.append_message(b"testing", b"initializing transcript for testing")?;
let proof = <PolyIOP<Fr> as ZeroCheck<Fr>>::prove(&poly, &mut transcript)?;
let poly_info = poly.domain_info.clone();
let mut transcript = <PolyIOP<Fr> as ZeroCheck<Fr>>::init_transcript();
transcript.append_message(b"testing", b"initializing transcript for testing")?;
let subclaim =
<PolyIOP<Fr> as ZeroCheck<Fr>>::verify(&proof, &poly_info, &mut transcript)?.0;
assert!(
poly.evaluate(&subclaim.point)? == subclaim.expected_evaluation,
"wrong subclaim"
);
}
{
// bad path: random virtual poly whose sum is not zero
let (poly, _sum) =
VirtualPolynomial::rand(nv, num_multiplicands_range, num_products, &mut rng)?;
let mut transcript = <PolyIOP<Fr> as ZeroCheck<Fr>>::init_transcript();
transcript.append_message(b"testing", b"initializing transcript for testing")?;
let proof = <PolyIOP<Fr> as ZeroCheck<Fr>>::prove(&poly, &mut transcript)?;
let poly_info = poly.domain_info.clone();
let mut transcript = <PolyIOP<Fr> as ZeroCheck<Fr>>::init_transcript();
transcript.append_message(b"testing", b"initializing transcript for testing")?;
assert!(
<PolyIOP<Fr> as ZeroCheck<Fr>>::verify(&proof, &poly_info, &mut transcript)
.is_err()
);
}
Ok(())
}
#[test]
fn test_trivial_polynomial() {
fn test_trivial_polynomial() -> Result<(), PolyIOPErrors> {
let nv = 1;
let num_multiplicands_range = (4, 5);
let num_products = 1;
test_polynomial(nv, num_multiplicands_range, num_products);
test_zerocheck(nv, num_multiplicands_range, num_products)
}
#[test]
fn test_normal_polynomial() {
let nv = 16;
fn test_normal_polynomial() -> Result<(), PolyIOPErrors> {
let nv = 5;
let num_multiplicands_range = (4, 9);
let num_products = 5;
test_polynomial(nv, num_multiplicands_range, num_products);
test_zerocheck(nv, num_multiplicands_range, num_products)
}
#[test]
#[should_panic]
fn zero_polynomial_should_error() {
fn zero_polynomial_should_error() -> Result<(), PolyIOPErrors> {
let nv = 0;
let num_multiplicands_range = (4, 13);
let num_products = 5;
test_polynomial(nv, num_multiplicands_range, num_products);
}
#[test]
/// Test that the memory usage of shared-reference is linear to number of
/// unique MLExtensions instead of total number of multiplicands.
fn test_shared_reference() {
let mut rng = test_rng();
let ml_extensions: Vec<_> = (0..5)
.map(|_| Rc::new(DenseMultilinearExtension::<Fr>::rand(8, &mut rng)))
.collect();
let mut poly = VirtualPolynomial::new(8);
poly.add_product(
vec![
ml_extensions[2].clone(),
ml_extensions[3].clone(),
ml_extensions[0].clone(),
],
Fr::rand(&mut rng),
);
poly.add_product(
vec![
ml_extensions[1].clone(),
ml_extensions[4].clone(),
ml_extensions[4].clone(),
],
Fr::rand(&mut rng),
);
poly.add_product(
vec![
ml_extensions[3].clone(),
ml_extensions[2].clone(),
ml_extensions[1].clone(),
],
Fr::rand(&mut rng),
);
poly.add_product(
vec![ml_extensions[0].clone(), ml_extensions[0].clone()],
Fr::rand(&mut rng),
);
poly.add_product(vec![ml_extensions[4].clone()], Fr::rand(&mut rng));
assert_eq!(poly.flattened_ml_extensions.len(), 5);
let mut transcript = PolyIOP::init_transcript();
transcript
.append_message(b"testing", b"initializing transcript for testing")
.unwrap();
let poly_info = poly.domain_info.clone();
let proof = PolyIOP::prove(&poly, &mut transcript).expect("fail to prove");
let mut transcript = PolyIOP::init_transcript();
transcript
.append_message(b"testing", b"initializing transcript for testing")
.unwrap();
let subclaim =
PolyIOP::verify(&proof, &poly_info, &mut transcript).expect("fail to verify");
assert!(
poly.evaluate(&subclaim.point) == subclaim.expected_evaluation,
"wrong subclaim"
);
assert!(test_zerocheck(nv, num_multiplicands_range, num_products).is_err());
Ok(())
}
}

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@@ -1,17 +0,0 @@
use ark_ff::PrimeField;
use ark_poly::DenseMultilinearExtension;
/// Prover State
pub struct ProverState<F: PrimeField> {
/// sampled randomness given by the verifier
pub challenges: Vec<F>,
/// Stores the list of products that is meant to be added together. Each
/// multiplicand is represented by the index in flattened_ml_extensions
pub list_of_products: Vec<(F, Vec<usize>)>,
/// Stores a list of multilinear extensions in which `self.list_of_products`
/// points to
pub flattened_ml_extensions: Vec<DenseMultilinearExtension<F>>,
pub(crate) num_vars: usize,
pub(crate) max_degree: usize,
pub(crate) round: usize,
}

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@@ -1,14 +0,0 @@
use ark_ff::PrimeField;
/// Verifier State
pub struct VerifierState<F: PrimeField> {
round: usize,
nv: usize,
max_degree: usize,
finished: bool,
/// a list storing the univariate polynomial in evaluation form sent by the
/// prover at each round
polynomials_received: Vec<Vec<F>>,
/// a list storing the randomness sampled by the verifier at each round
challenges: Vec<F>,
}