Add 'bellman/' from commit '10c5010fd9c2ca69442dc9775ea271e286e776d8'

git-subtree-dir: bellman
git-subtree-mainline: e924247e73
git-subtree-split: 10c5010fd9
This commit is contained in:
Jack Grigg
2018-08-28 23:03:52 +01:00
17 changed files with 4168 additions and 0 deletions
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use rand::Rng;
use std::sync::Arc;
use pairing::{
Engine,
PrimeField,
Field,
Wnaf,
CurveProjective,
CurveAffine
};
use super::{
Parameters,
VerifyingKey
};
use ::{
SynthesisError,
Circuit,
ConstraintSystem,
LinearCombination,
Variable,
Index
};
use ::domain::{
EvaluationDomain,
Scalar
};
use ::multicore::{
Worker
};
/// Generates a random common reference string for
/// a circuit.
pub fn generate_random_parameters<E, C, R>(
circuit: C,
rng: &mut R
) -> Result<Parameters<E>, SynthesisError>
where E: Engine, C: Circuit<E>, R: Rng
{
let g1 = rng.gen();
let g2 = rng.gen();
let alpha = rng.gen();
let beta = rng.gen();
let gamma = rng.gen();
let delta = rng.gen();
let tau = rng.gen();
generate_parameters::<E, C>(
circuit,
g1,
g2,
alpha,
beta,
gamma,
delta,
tau
)
}
/// This is our assembly structure that we'll use to synthesize the
/// circuit into a QAP.
struct KeypairAssembly<E: Engine> {
num_inputs: usize,
num_aux: usize,
num_constraints: usize,
at_inputs: Vec<Vec<(E::Fr, usize)>>,
bt_inputs: Vec<Vec<(E::Fr, usize)>>,
ct_inputs: Vec<Vec<(E::Fr, usize)>>,
at_aux: Vec<Vec<(E::Fr, usize)>>,
bt_aux: Vec<Vec<(E::Fr, usize)>>,
ct_aux: Vec<Vec<(E::Fr, usize)>>
}
impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
type Root = Self;
fn alloc<F, A, AR>(
&mut self,
_: A,
_: F
) -> Result<Variable, SynthesisError>
where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
{
// There is no assignment, so we don't even invoke the
// function for obtaining one.
let index = self.num_aux;
self.num_aux += 1;
self.at_aux.push(vec![]);
self.bt_aux.push(vec![]);
self.ct_aux.push(vec![]);
Ok(Variable(Index::Aux(index)))
}
fn alloc_input<F, A, AR>(
&mut self,
_: A,
_: F
) -> Result<Variable, SynthesisError>
where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
{
// There is no assignment, so we don't even invoke the
// function for obtaining one.
let index = self.num_inputs;
self.num_inputs += 1;
self.at_inputs.push(vec![]);
self.bt_inputs.push(vec![]);
self.ct_inputs.push(vec![]);
Ok(Variable(Index::Input(index)))
}
fn enforce<A, AR, LA, LB, LC>(
&mut self,
_: A,
a: LA,
b: LB,
c: LC
)
where A: FnOnce() -> AR, AR: Into<String>,
LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
{
fn eval<E: Engine>(
l: LinearCombination<E>,
inputs: &mut [Vec<(E::Fr, usize)>],
aux: &mut [Vec<(E::Fr, usize)>],
this_constraint: usize
)
{
for (index, coeff) in l.0 {
match index {
Variable(Index::Input(id)) => inputs[id].push((coeff, this_constraint)),
Variable(Index::Aux(id)) => aux[id].push((coeff, this_constraint))
}
}
}
eval(a(LinearCombination::zero()), &mut self.at_inputs, &mut self.at_aux, self.num_constraints);
eval(b(LinearCombination::zero()), &mut self.bt_inputs, &mut self.bt_aux, self.num_constraints);
eval(c(LinearCombination::zero()), &mut self.ct_inputs, &mut self.ct_aux, self.num_constraints);
self.num_constraints += 1;
}
fn push_namespace<NR, N>(&mut self, _: N)
where NR: Into<String>, N: FnOnce() -> NR
{
// Do nothing; we don't care about namespaces in this context.
}
fn pop_namespace(&mut self)
{
// Do nothing; we don't care about namespaces in this context.
}
fn get_root(&mut self) -> &mut Self::Root {
self
}
}
/// Create parameters for a circuit, given some toxic waste.
pub fn generate_parameters<E, C>(
circuit: C,
g1: E::G1,
g2: E::G2,
alpha: E::Fr,
beta: E::Fr,
gamma: E::Fr,
delta: E::Fr,
tau: E::Fr
) -> Result<Parameters<E>, SynthesisError>
where E: Engine, C: Circuit<E>
{
let mut assembly = KeypairAssembly {
num_inputs: 0,
num_aux: 0,
num_constraints: 0,
at_inputs: vec![],
bt_inputs: vec![],
ct_inputs: vec![],
at_aux: vec![],
bt_aux: vec![],
ct_aux: vec![]
};
// Allocate the "one" input variable
assembly.alloc_input(|| "", || Ok(E::Fr::one()))?;
// Synthesize the circuit.
circuit.synthesize(&mut assembly)?;
// Input constraints to ensure full density of IC query
// x * 0 = 0
for i in 0..assembly.num_inputs {
assembly.enforce(|| "",
|lc| lc + Variable(Index::Input(i)),
|lc| lc,
|lc| lc,
);
}
// Create bases for blind evaluation of polynomials at tau
let powers_of_tau = vec![Scalar::<E>(E::Fr::zero()); assembly.num_constraints];
let mut powers_of_tau = EvaluationDomain::from_coeffs(powers_of_tau)?;
// Compute G1 window table
let mut g1_wnaf = Wnaf::new();
let g1_wnaf = g1_wnaf.base(g1, {
// H query
(powers_of_tau.as_ref().len() - 1)
// IC/L queries
+ assembly.num_inputs + assembly.num_aux
// A query
+ assembly.num_inputs + assembly.num_aux
// B query
+ assembly.num_inputs + assembly.num_aux
});
// Compute G2 window table
let mut g2_wnaf = Wnaf::new();
let g2_wnaf = g2_wnaf.base(g2, {
// B query
assembly.num_inputs + assembly.num_aux
});
let gamma_inverse = gamma.inverse().ok_or(SynthesisError::UnexpectedIdentity)?;
let delta_inverse = delta.inverse().ok_or(SynthesisError::UnexpectedIdentity)?;
let worker = Worker::new();
let mut h = vec![E::G1::zero(); powers_of_tau.as_ref().len() - 1];
{
// Compute powers of tau
{
let powers_of_tau = powers_of_tau.as_mut();
worker.scope(powers_of_tau.len(), |scope, chunk| {
for (i, powers_of_tau) in powers_of_tau.chunks_mut(chunk).enumerate()
{
scope.spawn(move || {
let mut current_tau_power = tau.pow(&[(i*chunk) as u64]);
for p in powers_of_tau {
p.0 = current_tau_power;
current_tau_power.mul_assign(&tau);
}
});
}
});
}
// coeff = t(x) / delta
let mut coeff = powers_of_tau.z(&tau);
coeff.mul_assign(&delta_inverse);
// Compute the H query with multiple threads
worker.scope(h.len(), |scope, chunk| {
for (h, p) in h.chunks_mut(chunk).zip(powers_of_tau.as_ref().chunks(chunk))
{
let mut g1_wnaf = g1_wnaf.shared();
scope.spawn(move || {
// Set values of the H query to g1^{(tau^i * t(tau)) / delta}
for (h, p) in h.iter_mut().zip(p.iter())
{
// Compute final exponent
let mut exp = p.0;
exp.mul_assign(&coeff);
// Exponentiate
*h = g1_wnaf.scalar(exp.into_repr());
}
// Batch normalize
E::G1::batch_normalization(h);
});
}
});
}
// Use inverse FFT to convert powers of tau to Lagrange coefficients
powers_of_tau.ifft(&worker);
let powers_of_tau = powers_of_tau.into_coeffs();
let mut a = vec![E::G1::zero(); assembly.num_inputs + assembly.num_aux];
let mut b_g1 = vec![E::G1::zero(); assembly.num_inputs + assembly.num_aux];
let mut b_g2 = vec![E::G2::zero(); assembly.num_inputs + assembly.num_aux];
let mut ic = vec![E::G1::zero(); assembly.num_inputs];
let mut l = vec![E::G1::zero(); assembly.num_aux];
fn eval<E: Engine>(
// wNAF window tables
g1_wnaf: &Wnaf<usize, &[E::G1], &mut Vec<i64>>,
g2_wnaf: &Wnaf<usize, &[E::G2], &mut Vec<i64>>,
// Lagrange coefficients for tau
powers_of_tau: &[Scalar<E>],
// QAP polynomials
at: &[Vec<(E::Fr, usize)>],
bt: &[Vec<(E::Fr, usize)>],
ct: &[Vec<(E::Fr, usize)>],
// Resulting evaluated QAP polynomials
a: &mut [E::G1],
b_g1: &mut [E::G1],
b_g2: &mut [E::G2],
ext: &mut [E::G1],
// Inverse coefficient for ext elements
inv: &E::Fr,
// Trapdoors
alpha: &E::Fr,
beta: &E::Fr,
// Worker
worker: &Worker
)
{
// Sanity check
assert_eq!(a.len(), at.len());
assert_eq!(a.len(), bt.len());
assert_eq!(a.len(), ct.len());
assert_eq!(a.len(), b_g1.len());
assert_eq!(a.len(), b_g2.len());
assert_eq!(a.len(), ext.len());
// Evaluate polynomials in multiple threads
worker.scope(a.len(), |scope, chunk| {
for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a.chunks_mut(chunk)
.zip(b_g1.chunks_mut(chunk))
.zip(b_g2.chunks_mut(chunk))
.zip(ext.chunks_mut(chunk))
.zip(at.chunks(chunk))
.zip(bt.chunks(chunk))
.zip(ct.chunks(chunk))
{
let mut g1_wnaf = g1_wnaf.shared();
let mut g2_wnaf = g2_wnaf.shared();
scope.spawn(move || {
for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a.iter_mut()
.zip(b_g1.iter_mut())
.zip(b_g2.iter_mut())
.zip(ext.iter_mut())
.zip(at.iter())
.zip(bt.iter())
.zip(ct.iter())
{
fn eval_at_tau<E: Engine>(
powers_of_tau: &[Scalar<E>],
p: &[(E::Fr, usize)]
) -> E::Fr
{
let mut acc = E::Fr::zero();
for &(ref coeff, index) in p {
let mut n = powers_of_tau[index].0;
n.mul_assign(coeff);
acc.add_assign(&n);
}
acc
}
// Evaluate QAP polynomials at tau
let mut at = eval_at_tau(powers_of_tau, at);
let mut bt = eval_at_tau(powers_of_tau, bt);
let ct = eval_at_tau(powers_of_tau, ct);
// Compute A query (in G1)
if !at.is_zero() {
*a = g1_wnaf.scalar(at.into_repr());
}
// Compute B query (in G1/G2)
if !bt.is_zero() {
let bt_repr = bt.into_repr();
*b_g1 = g1_wnaf.scalar(bt_repr);
*b_g2 = g2_wnaf.scalar(bt_repr);
}
at.mul_assign(&beta);
bt.mul_assign(&alpha);
let mut e = at;
e.add_assign(&bt);
e.add_assign(&ct);
e.mul_assign(inv);
*ext = g1_wnaf.scalar(e.into_repr());
}
// Batch normalize
E::G1::batch_normalization(a);
E::G1::batch_normalization(b_g1);
E::G2::batch_normalization(b_g2);
E::G1::batch_normalization(ext);
});
}
});
}
// Evaluate for inputs.
eval(
&g1_wnaf,
&g2_wnaf,
&powers_of_tau,
&assembly.at_inputs,
&assembly.bt_inputs,
&assembly.ct_inputs,
&mut a[0..assembly.num_inputs],
&mut b_g1[0..assembly.num_inputs],
&mut b_g2[0..assembly.num_inputs],
&mut ic,
&gamma_inverse,
&alpha,
&beta,
&worker
);
// Evaluate for auxillary variables.
eval(
&g1_wnaf,
&g2_wnaf,
&powers_of_tau,
&assembly.at_aux,
&assembly.bt_aux,
&assembly.ct_aux,
&mut a[assembly.num_inputs..],
&mut b_g1[assembly.num_inputs..],
&mut b_g2[assembly.num_inputs..],
&mut l,
&delta_inverse,
&alpha,
&beta,
&worker
);
// Don't allow any elements be unconstrained, so that
// the L query is always fully dense.
for e in l.iter() {
if e.is_zero() {
return Err(SynthesisError::UnconstrainedVariable);
}
}
let g1 = g1.into_affine();
let g2 = g2.into_affine();
let vk = VerifyingKey::<E> {
alpha_g1: g1.mul(alpha).into_affine(),
beta_g1: g1.mul(beta).into_affine(),
beta_g2: g2.mul(beta).into_affine(),
gamma_g2: g2.mul(gamma).into_affine(),
delta_g1: g1.mul(delta).into_affine(),
delta_g2: g2.mul(delta).into_affine(),
ic: ic.into_iter().map(|e| e.into_affine()).collect()
};
Ok(Parameters {
vk: vk,
h: Arc::new(h.into_iter().map(|e| e.into_affine()).collect()),
l: Arc::new(l.into_iter().map(|e| e.into_affine()).collect()),
// Filter points at infinity away from A/B queries
a: Arc::new(a.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect()),
b_g1: Arc::new(b_g1.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect()),
b_g2: Arc::new(b_g2.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect())
})
}
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use pairing::{
Engine,
CurveAffine,
EncodedPoint
};
use ::{
SynthesisError
};
use multiexp::SourceBuilder;
use std::io::{self, Read, Write};
use std::sync::Arc;
use byteorder::{BigEndian, WriteBytesExt, ReadBytesExt};
#[cfg(test)]
mod tests;
mod generator;
mod prover;
mod verifier;
pub use self::generator::*;
pub use self::prover::*;
pub use self::verifier::*;
#[derive(Clone)]
pub struct Proof<E: Engine> {
pub a: E::G1Affine,
pub b: E::G2Affine,
pub c: E::G1Affine
}
impl<E: Engine> PartialEq for Proof<E> {
fn eq(&self, other: &Self) -> bool {
self.a == other.a &&
self.b == other.b &&
self.c == other.c
}
}
impl<E: Engine> Proof<E> {
pub fn write<W: Write>(
&self,
mut writer: W
) -> io::Result<()>
{
writer.write_all(self.a.into_compressed().as_ref())?;
writer.write_all(self.b.into_compressed().as_ref())?;
writer.write_all(self.c.into_compressed().as_ref())?;
Ok(())
}
pub fn read<R: Read>(
mut reader: R
) -> io::Result<Self>
{
let mut g1_repr = <E::G1Affine as CurveAffine>::Compressed::empty();
let mut g2_repr = <E::G2Affine as CurveAffine>::Compressed::empty();
reader.read_exact(g1_repr.as_mut())?;
let a = g1_repr
.into_affine()
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})?;
reader.read_exact(g2_repr.as_mut())?;
let b = g2_repr
.into_affine()
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})?;
reader.read_exact(g1_repr.as_mut())?;
let c = g1_repr
.into_affine()
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})?;
Ok(Proof {
a: a,
b: b,
c: c
})
}
}
#[derive(Clone)]
pub struct VerifyingKey<E: Engine> {
// alpha in g1 for verifying and for creating A/C elements of
// proof. Never the point at infinity.
pub alpha_g1: E::G1Affine,
// beta in g1 and g2 for verifying and for creating B/C elements
// of proof. Never the point at infinity.
pub beta_g1: E::G1Affine,
pub beta_g2: E::G2Affine,
// gamma in g2 for verifying. Never the point at infinity.
pub gamma_g2: E::G2Affine,
// delta in g1/g2 for verifying and proving, essentially the magic
// trapdoor that forces the prover to evaluate the C element of the
// proof with only components from the CRS. Never the point at
// infinity.
pub delta_g1: E::G1Affine,
pub delta_g2: E::G2Affine,
// Elements of the form (beta * u_i(tau) + alpha v_i(tau) + w_i(tau)) / gamma
// for all public inputs. Because all public inputs have a dummy constraint,
// this is the same size as the number of inputs, and never contains points
// at infinity.
pub ic: Vec<E::G1Affine>
}
impl<E: Engine> PartialEq for VerifyingKey<E> {
fn eq(&self, other: &Self) -> bool {
self.alpha_g1 == other.alpha_g1 &&
self.beta_g1 == other.beta_g1 &&
self.beta_g2 == other.beta_g2 &&
self.gamma_g2 == other.gamma_g2 &&
self.delta_g1 == other.delta_g1 &&
self.delta_g2 == other.delta_g2 &&
self.ic == other.ic
}
}
impl<E: Engine> VerifyingKey<E> {
pub fn write<W: Write>(
&self,
mut writer: W
) -> io::Result<()>
{
writer.write_all(self.alpha_g1.into_uncompressed().as_ref())?;
writer.write_all(self.beta_g1.into_uncompressed().as_ref())?;
writer.write_all(self.beta_g2.into_uncompressed().as_ref())?;
writer.write_all(self.gamma_g2.into_uncompressed().as_ref())?;
writer.write_all(self.delta_g1.into_uncompressed().as_ref())?;
writer.write_all(self.delta_g2.into_uncompressed().as_ref())?;
writer.write_u32::<BigEndian>(self.ic.len() as u32)?;
for ic in &self.ic {
writer.write_all(ic.into_uncompressed().as_ref())?;
}
Ok(())
}
pub fn read<R: Read>(
mut reader: R
) -> io::Result<Self>
{
let mut g1_repr = <E::G1Affine as CurveAffine>::Uncompressed::empty();
let mut g2_repr = <E::G2Affine as CurveAffine>::Uncompressed::empty();
reader.read_exact(g1_repr.as_mut())?;
let alpha_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
reader.read_exact(g1_repr.as_mut())?;
let beta_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
reader.read_exact(g2_repr.as_mut())?;
let beta_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
reader.read_exact(g2_repr.as_mut())?;
let gamma_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
reader.read_exact(g1_repr.as_mut())?;
let delta_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
reader.read_exact(g2_repr.as_mut())?;
let delta_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
let ic_len = reader.read_u32::<BigEndian>()? as usize;
let mut ic = vec![];
for _ in 0..ic_len {
reader.read_exact(g1_repr.as_mut())?;
let g1 = g1_repr
.into_affine()
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})?;
ic.push(g1);
}
Ok(VerifyingKey {
alpha_g1: alpha_g1,
beta_g1: beta_g1,
beta_g2: beta_g2,
gamma_g2: gamma_g2,
delta_g1: delta_g1,
delta_g2: delta_g2,
ic: ic
})
}
}
#[derive(Clone)]
pub struct Parameters<E: Engine> {
pub vk: VerifyingKey<E>,
// Elements of the form ((tau^i * t(tau)) / delta) for i between 0 and
// m-2 inclusive. Never contains points at infinity.
pub h: Arc<Vec<E::G1Affine>>,
// Elements of the form (beta * u_i(tau) + alpha v_i(tau) + w_i(tau)) / delta
// for all auxillary inputs. Variables can never be unconstrained, so this
// never contains points at infinity.
pub l: Arc<Vec<E::G1Affine>>,
// QAP "A" polynomials evaluated at tau in the Lagrange basis. Never contains
// points at infinity: polynomials that evaluate to zero are omitted from
// the CRS and the prover can deterministically skip their evaluation.
pub a: Arc<Vec<E::G1Affine>>,
// QAP "B" polynomials evaluated at tau in the Lagrange basis. Needed in
// G1 and G2 for C/B queries, respectively. Never contains points at
// infinity for the same reason as the "A" polynomials.
pub b_g1: Arc<Vec<E::G1Affine>>,
pub b_g2: Arc<Vec<E::G2Affine>>
}
impl<E: Engine> PartialEq for Parameters<E> {
fn eq(&self, other: &Self) -> bool {
self.vk == other.vk &&
self.h == other.h &&
self.l == other.l &&
self.a == other.a &&
self.b_g1 == other.b_g1 &&
self.b_g2 == other.b_g2
}
}
impl<E: Engine> Parameters<E> {
pub fn write<W: Write>(
&self,
mut writer: W
) -> io::Result<()>
{
self.vk.write(&mut writer)?;
writer.write_u32::<BigEndian>(self.h.len() as u32)?;
for g in &self.h[..] {
writer.write_all(g.into_uncompressed().as_ref())?;
}
writer.write_u32::<BigEndian>(self.l.len() as u32)?;
for g in &self.l[..] {
writer.write_all(g.into_uncompressed().as_ref())?;
}
writer.write_u32::<BigEndian>(self.a.len() as u32)?;
for g in &self.a[..] {
writer.write_all(g.into_uncompressed().as_ref())?;
}
writer.write_u32::<BigEndian>(self.b_g1.len() as u32)?;
for g in &self.b_g1[..] {
writer.write_all(g.into_uncompressed().as_ref())?;
}
writer.write_u32::<BigEndian>(self.b_g2.len() as u32)?;
for g in &self.b_g2[..] {
writer.write_all(g.into_uncompressed().as_ref())?;
}
Ok(())
}
pub fn read<R: Read>(
mut reader: R,
checked: bool
) -> io::Result<Self>
{
let read_g1 = |reader: &mut R| -> io::Result<E::G1Affine> {
let mut repr = <E::G1Affine as CurveAffine>::Uncompressed::empty();
reader.read_exact(repr.as_mut())?;
if checked {
repr
.into_affine()
} else {
repr
.into_affine_unchecked()
}
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})
};
let read_g2 = |reader: &mut R| -> io::Result<E::G2Affine> {
let mut repr = <E::G2Affine as CurveAffine>::Uncompressed::empty();
reader.read_exact(repr.as_mut())?;
if checked {
repr
.into_affine()
} else {
repr
.into_affine_unchecked()
}
.map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
.and_then(|e| if e.is_zero() {
Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
} else {
Ok(e)
})
};
let vk = VerifyingKey::<E>::read(&mut reader)?;
let mut h = vec![];
let mut l = vec![];
let mut a = vec![];
let mut b_g1 = vec![];
let mut b_g2 = vec![];
{
let len = reader.read_u32::<BigEndian>()? as usize;
for _ in 0..len {
h.push(read_g1(&mut reader)?);
}
}
{
let len = reader.read_u32::<BigEndian>()? as usize;
for _ in 0..len {
l.push(read_g1(&mut reader)?);
}
}
{
let len = reader.read_u32::<BigEndian>()? as usize;
for _ in 0..len {
a.push(read_g1(&mut reader)?);
}
}
{
let len = reader.read_u32::<BigEndian>()? as usize;
for _ in 0..len {
b_g1.push(read_g1(&mut reader)?);
}
}
{
let len = reader.read_u32::<BigEndian>()? as usize;
for _ in 0..len {
b_g2.push(read_g2(&mut reader)?);
}
}
Ok(Parameters {
vk: vk,
h: Arc::new(h),
l: Arc::new(l),
a: Arc::new(a),
b_g1: Arc::new(b_g1),
b_g2: Arc::new(b_g2)
})
}
}
pub struct PreparedVerifyingKey<E: Engine> {
/// Pairing result of alpha*beta
alpha_g1_beta_g2: E::Fqk,
/// -gamma in G2
neg_gamma_g2: <E::G2Affine as CurveAffine>::Prepared,
/// -delta in G2
neg_delta_g2: <E::G2Affine as CurveAffine>::Prepared,
/// Copy of IC from `VerifiyingKey`.
ic: Vec<E::G1Affine>
}
pub trait ParameterSource<E: Engine> {
type G1Builder: SourceBuilder<E::G1Affine>;
type G2Builder: SourceBuilder<E::G2Affine>;
fn get_vk(
&mut self,
num_ic: usize
) -> Result<VerifyingKey<E>, SynthesisError>;
fn get_h(
&mut self,
num_h: usize
) -> Result<Self::G1Builder, SynthesisError>;
fn get_l(
&mut self,
num_l: usize
) -> Result<Self::G1Builder, SynthesisError>;
fn get_a(
&mut self,
num_inputs: usize,
num_aux: usize
) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>;
fn get_b_g1(
&mut self,
num_inputs: usize,
num_aux: usize
) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>;
fn get_b_g2(
&mut self,
num_inputs: usize,
num_aux: usize
) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError>;
}
impl<'a, E: Engine> ParameterSource<E> for &'a Parameters<E> {
type G1Builder = (Arc<Vec<E::G1Affine>>, usize);
type G2Builder = (Arc<Vec<E::G2Affine>>, usize);
fn get_vk(
&mut self,
_: usize
) -> Result<VerifyingKey<E>, SynthesisError>
{
Ok(self.vk.clone())
}
fn get_h(
&mut self,
_: usize
) -> Result<Self::G1Builder, SynthesisError>
{
Ok((self.h.clone(), 0))
}
fn get_l(
&mut self,
_: usize
) -> Result<Self::G1Builder, SynthesisError>
{
Ok((self.l.clone(), 0))
}
fn get_a(
&mut self,
num_inputs: usize,
_: usize
) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
{
Ok(((self.a.clone(), 0), (self.a.clone(), num_inputs)))
}
fn get_b_g1(
&mut self,
num_inputs: usize,
_: usize
) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
{
Ok(((self.b_g1.clone(), 0), (self.b_g1.clone(), num_inputs)))
}
fn get_b_g2(
&mut self,
num_inputs: usize,
_: usize
) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError>
{
Ok(((self.b_g2.clone(), 0), (self.b_g2.clone(), num_inputs)))
}
}
#[cfg(test)]
mod test_with_bls12_381 {
use super::*;
use {Circuit, SynthesisError, ConstraintSystem};
use rand::{Rand, thread_rng};
use pairing::{Field};
use pairing::bls12_381::{Bls12, Fr};
#[test]
fn serialization() {
struct MySillyCircuit<E: Engine> {
a: Option<E::Fr>,
b: Option<E::Fr>
}
impl<E: Engine> Circuit<E> for MySillyCircuit<E> {
fn synthesize<CS: ConstraintSystem<E>>(
self,
cs: &mut CS
) -> Result<(), SynthesisError>
{
let a = cs.alloc(|| "a", || self.a.ok_or(SynthesisError::AssignmentMissing))?;
let b = cs.alloc(|| "b", || self.b.ok_or(SynthesisError::AssignmentMissing))?;
let c = cs.alloc_input(|| "c", || {
let mut a = self.a.ok_or(SynthesisError::AssignmentMissing)?;
let b = self.b.ok_or(SynthesisError::AssignmentMissing)?;
a.mul_assign(&b);
Ok(a)
})?;
cs.enforce(
|| "a*b=c",
|lc| lc + a,
|lc| lc + b,
|lc| lc + c
);
Ok(())
}
}
let rng = &mut thread_rng();
let params = generate_random_parameters::<Bls12, _, _>(
MySillyCircuit { a: None, b: None },
rng
).unwrap();
{
let mut v = vec![];
params.write(&mut v).unwrap();
assert_eq!(v.len(), 2136);
let de_params = Parameters::read(&v[..], true).unwrap();
assert!(params == de_params);
let de_params = Parameters::read(&v[..], false).unwrap();
assert!(params == de_params);
}
let pvk = prepare_verifying_key::<Bls12>(&params.vk);
for _ in 0..100 {
let a = Fr::rand(rng);
let b = Fr::rand(rng);
let mut c = a;
c.mul_assign(&b);
let proof = create_random_proof(
MySillyCircuit {
a: Some(a),
b: Some(b)
},
&params,
rng
).unwrap();
let mut v = vec![];
proof.write(&mut v).unwrap();
assert_eq!(v.len(), 192);
let de_proof = Proof::read(&v[..]).unwrap();
assert!(proof == de_proof);
assert!(verify_proof(&pvk, &proof, &[c]).unwrap());
assert!(!verify_proof(&pvk, &proof, &[a]).unwrap());
}
}
}
+334
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@@ -0,0 +1,334 @@
use rand::Rng;
use std::sync::Arc;
use futures::Future;
use pairing::{
Engine,
PrimeField,
Field,
CurveProjective,
CurveAffine
};
use super::{
ParameterSource,
Proof
};
use ::{
SynthesisError,
Circuit,
ConstraintSystem,
LinearCombination,
Variable,
Index
};
use ::domain::{
EvaluationDomain,
Scalar
};
use ::multiexp::{
DensityTracker,
FullDensity,
multiexp
};
use ::multicore::{
Worker
};
fn eval<E: Engine>(
lc: &LinearCombination<E>,
mut input_density: Option<&mut DensityTracker>,
mut aux_density: Option<&mut DensityTracker>,
input_assignment: &[E::Fr],
aux_assignment: &[E::Fr]
) -> E::Fr
{
let mut acc = E::Fr::zero();
for &(index, coeff) in lc.0.iter() {
let mut tmp;
match index {
Variable(Index::Input(i)) => {
tmp = input_assignment[i];
if let Some(ref mut v) = input_density {
v.inc(i);
}
},
Variable(Index::Aux(i)) => {
tmp = aux_assignment[i];
if let Some(ref mut v) = aux_density {
v.inc(i);
}
}
}
if coeff == E::Fr::one() {
acc.add_assign(&tmp);
} else {
tmp.mul_assign(&coeff);
acc.add_assign(&tmp);
}
}
acc
}
struct ProvingAssignment<E: Engine> {
// Density of queries
a_aux_density: DensityTracker,
b_input_density: DensityTracker,
b_aux_density: DensityTracker,
// Evaluations of A, B, C polynomials
a: Vec<Scalar<E>>,
b: Vec<Scalar<E>>,
c: Vec<Scalar<E>>,
// Assignments of variables
input_assignment: Vec<E::Fr>,
aux_assignment: Vec<E::Fr>
}
impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
type Root = Self;
fn alloc<F, A, AR>(
&mut self,
_: A,
f: F
) -> Result<Variable, SynthesisError>
where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
{
self.aux_assignment.push(f()?);
self.a_aux_density.add_element();
self.b_aux_density.add_element();
Ok(Variable(Index::Aux(self.aux_assignment.len() - 1)))
}
fn alloc_input<F, A, AR>(
&mut self,
_: A,
f: F
) -> Result<Variable, SynthesisError>
where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
{
self.input_assignment.push(f()?);
self.b_input_density.add_element();
Ok(Variable(Index::Input(self.input_assignment.len() - 1)))
}
fn enforce<A, AR, LA, LB, LC>(
&mut self,
_: A,
a: LA,
b: LB,
c: LC
)
where A: FnOnce() -> AR, AR: Into<String>,
LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
{
let a = a(LinearCombination::zero());
let b = b(LinearCombination::zero());
let c = c(LinearCombination::zero());
self.a.push(Scalar(eval(
&a,
// Inputs have full density in the A query
// because there are constraints of the
// form x * 0 = 0 for each input.
None,
Some(&mut self.a_aux_density),
&self.input_assignment,
&self.aux_assignment
)));
self.b.push(Scalar(eval(
&b,
Some(&mut self.b_input_density),
Some(&mut self.b_aux_density),
&self.input_assignment,
&self.aux_assignment
)));
self.c.push(Scalar(eval(
&c,
// There is no C polynomial query,
// though there is an (beta)A + (alpha)B + C
// query for all aux variables.
// However, that query has full density.
None,
None,
&self.input_assignment,
&self.aux_assignment
)));
}
fn push_namespace<NR, N>(&mut self, _: N)
where NR: Into<String>, N: FnOnce() -> NR
{
// Do nothing; we don't care about namespaces in this context.
}
fn pop_namespace(&mut self)
{
// Do nothing; we don't care about namespaces in this context.
}
fn get_root(&mut self) -> &mut Self::Root {
self
}
}
pub fn create_random_proof<E, C, R, P: ParameterSource<E>>(
circuit: C,
params: P,
rng: &mut R
) -> Result<Proof<E>, SynthesisError>
where E: Engine, C: Circuit<E>, R: Rng
{
let r = rng.gen();
let s = rng.gen();
create_proof::<E, C, P>(circuit, params, r, s)
}
pub fn create_proof<E, C, P: ParameterSource<E>>(
circuit: C,
mut params: P,
r: E::Fr,
s: E::Fr
) -> Result<Proof<E>, SynthesisError>
where E: Engine, C: Circuit<E>
{
let mut prover = ProvingAssignment {
a_aux_density: DensityTracker::new(),
b_input_density: DensityTracker::new(),
b_aux_density: DensityTracker::new(),
a: vec![],
b: vec![],
c: vec![],
input_assignment: vec![],
aux_assignment: vec![]
};
prover.alloc_input(|| "", || Ok(E::Fr::one()))?;
circuit.synthesize(&mut prover)?;
for i in 0..prover.input_assignment.len() {
prover.enforce(|| "",
|lc| lc + Variable(Index::Input(i)),
|lc| lc,
|lc| lc,
);
}
let worker = Worker::new();
let vk = params.get_vk(prover.input_assignment.len())?;
let h = {
let mut a = EvaluationDomain::from_coeffs(prover.a)?;
let mut b = EvaluationDomain::from_coeffs(prover.b)?;
let mut c = EvaluationDomain::from_coeffs(prover.c)?;
a.ifft(&worker);
a.coset_fft(&worker);
b.ifft(&worker);
b.coset_fft(&worker);
c.ifft(&worker);
c.coset_fft(&worker);
a.mul_assign(&worker, &b);
drop(b);
a.sub_assign(&worker, &c);
drop(c);
a.divide_by_z_on_coset(&worker);
a.icoset_fft(&worker);
let mut a = a.into_coeffs();
let a_len = a.len() - 1;
a.truncate(a_len);
// TODO: parallelize if it's even helpful
let a = Arc::new(a.into_iter().map(|s| s.0.into_repr()).collect::<Vec<_>>());
multiexp(&worker, params.get_h(a.len())?, FullDensity, a)
};
// TODO: parallelize if it's even helpful
let input_assignment = Arc::new(prover.input_assignment.into_iter().map(|s| s.into_repr()).collect::<Vec<_>>());
let aux_assignment = Arc::new(prover.aux_assignment.into_iter().map(|s| s.into_repr()).collect::<Vec<_>>());
let l = multiexp(&worker, params.get_l(aux_assignment.len())?, FullDensity, aux_assignment.clone());
let a_aux_density_total = prover.a_aux_density.get_total_density();
let (a_inputs_source, a_aux_source) = params.get_a(input_assignment.len(), a_aux_density_total)?;
let a_inputs = multiexp(&worker, a_inputs_source, FullDensity, input_assignment.clone());
let a_aux = multiexp(&worker, a_aux_source, Arc::new(prover.a_aux_density), aux_assignment.clone());
let b_input_density = Arc::new(prover.b_input_density);
let b_input_density_total = b_input_density.get_total_density();
let b_aux_density = Arc::new(prover.b_aux_density);
let b_aux_density_total = b_aux_density.get_total_density();
let (b_g1_inputs_source, b_g1_aux_source) = params.get_b_g1(b_input_density_total, b_aux_density_total)?;
let b_g1_inputs = multiexp(&worker, b_g1_inputs_source, b_input_density.clone(), input_assignment.clone());
let b_g1_aux = multiexp(&worker, b_g1_aux_source, b_aux_density.clone(), aux_assignment.clone());
let (b_g2_inputs_source, b_g2_aux_source) = params.get_b_g2(b_input_density_total, b_aux_density_total)?;
let b_g2_inputs = multiexp(&worker, b_g2_inputs_source, b_input_density, input_assignment);
let b_g2_aux = multiexp(&worker, b_g2_aux_source, b_aux_density, aux_assignment);
if vk.delta_g1.is_zero() || vk.delta_g2.is_zero() {
// If this element is zero, someone is trying to perform a
// subversion-CRS attack.
return Err(SynthesisError::UnexpectedIdentity);
}
let mut g_a = vk.delta_g1.mul(r);
g_a.add_assign_mixed(&vk.alpha_g1);
let mut g_b = vk.delta_g2.mul(s);
g_b.add_assign_mixed(&vk.beta_g2);
let mut g_c;
{
let mut rs = r;
rs.mul_assign(&s);
g_c = vk.delta_g1.mul(rs);
g_c.add_assign(&vk.alpha_g1.mul(s));
g_c.add_assign(&vk.beta_g1.mul(r));
}
let mut a_answer = a_inputs.wait()?;
a_answer.add_assign(&a_aux.wait()?);
g_a.add_assign(&a_answer);
a_answer.mul_assign(s);
g_c.add_assign(&a_answer);
let mut b1_answer = b_g1_inputs.wait()?;
b1_answer.add_assign(&b_g1_aux.wait()?);
let mut b2_answer = b_g2_inputs.wait()?;
b2_answer.add_assign(&b_g2_aux.wait()?);
g_b.add_assign(&b2_answer);
b1_answer.mul_assign(r);
g_c.add_assign(&b1_answer);
g_c.add_assign(&h.wait()?);
g_c.add_assign(&l.wait()?);
Ok(Proof {
a: g_a.into_affine(),
b: g_b.into_affine(),
c: g_c.into_affine()
})
}
+451
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@@ -0,0 +1,451 @@
use pairing::{
Engine,
PrimeField,
PrimeFieldRepr,
Field,
SqrtField,
LegendreSymbol,
CurveProjective,
CurveAffine,
PrimeFieldDecodingError,
GroupDecodingError,
EncodedPoint
};
use std::cmp::Ordering;
use std::fmt;
use rand::{Rand, Rng};
use std::num::Wrapping;
const MODULUS_R: Wrapping<u32> = Wrapping(64513);
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub struct Fr(Wrapping<u32>);
impl fmt::Display for Fr {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "{}", (self.0).0)
}
}
impl Rand for Fr {
fn rand<R: Rng>(rng: &mut R) -> Self {
Fr(Wrapping(rng.gen()) % MODULUS_R)
}
}
impl Field for Fr {
fn zero() -> Self {
Fr(Wrapping(0))
}
fn one() -> Self {
Fr(Wrapping(1))
}
fn is_zero(&self) -> bool {
(self.0).0 == 0
}
fn square(&mut self) {
self.0 = (self.0 * self.0) % MODULUS_R;
}
fn double(&mut self) {
self.0 = (self.0 << 1) % MODULUS_R;
}
fn negate(&mut self) {
if !<Fr as Field>::is_zero(self) {
self.0 = MODULUS_R - self.0;
}
}
fn add_assign(&mut self, other: &Self) {
self.0 = (self.0 + other.0) % MODULUS_R;
}
fn sub_assign(&mut self, other: &Self) {
self.0 = ((MODULUS_R + self.0) - other.0) % MODULUS_R;
}
fn mul_assign(&mut self, other: &Self) {
self.0 = (self.0 * other.0) % MODULUS_R;
}
fn inverse(&self) -> Option<Self> {
if <Fr as Field>::is_zero(self) {
None
} else {
Some(self.pow(&[(MODULUS_R.0 as u64) - 2]))
}
}
fn frobenius_map(&mut self, _: usize) {
// identity
}
}
impl SqrtField for Fr {
fn legendre(&self) -> LegendreSymbol {
// s = self^((r - 1) // 2)
let s = self.pow([32256]);
if s == <Fr as Field>::zero() { LegendreSymbol::Zero }
else if s == <Fr as Field>::one() { LegendreSymbol::QuadraticResidue }
else { LegendreSymbol::QuadraticNonResidue }
}
fn sqrt(&self) -> Option<Self> {
// Tonelli-Shank's algorithm for q mod 16 = 1
// https://eprint.iacr.org/2012/685.pdf (page 12, algorithm 5)
match self.legendre() {
LegendreSymbol::Zero => Some(*self),
LegendreSymbol::QuadraticNonResidue => None,
LegendreSymbol::QuadraticResidue => {
let mut c = Fr::root_of_unity();
// r = self^((t + 1) // 2)
let mut r = self.pow([32]);
// t = self^t
let mut t = self.pow([63]);
let mut m = Fr::S;
while t != <Fr as Field>::one() {
let mut i = 1;
{
let mut t2i = t;
t2i.square();
loop {
if t2i == <Fr as Field>::one() {
break;
}
t2i.square();
i += 1;
}
}
for _ in 0..(m - i - 1) {
c.square();
}
<Fr as Field>::mul_assign(&mut r, &c);
c.square();
<Fr as Field>::mul_assign(&mut t, &c);
m = i;
}
Some(r)
}
}
}
}
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub struct FrRepr([u64; 1]);
impl Ord for FrRepr {
fn cmp(&self, other: &FrRepr) -> Ordering {
(self.0)[0].cmp(&(other.0)[0])
}
}
impl PartialOrd for FrRepr {
fn partial_cmp(&self, other: &FrRepr) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Rand for FrRepr {
fn rand<R: Rng>(rng: &mut R) -> Self {
FrRepr([rng.gen()])
}
}
impl fmt::Display for FrRepr {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
write!(f, "{}", (self.0)[0])
}
}
impl From<u64> for FrRepr {
fn from(v: u64) -> FrRepr {
FrRepr([v])
}
}
impl From<Fr> for FrRepr {
fn from(v: Fr) -> FrRepr {
FrRepr([(v.0).0 as u64])
}
}
impl AsMut<[u64]> for FrRepr {
fn as_mut(&mut self) -> &mut [u64] {
&mut self.0[..]
}
}
impl AsRef<[u64]> for FrRepr {
fn as_ref(&self) -> &[u64] {
&self.0[..]
}
}
impl Default for FrRepr {
fn default() -> FrRepr {
FrRepr::from(0u64)
}
}
impl PrimeFieldRepr for FrRepr {
fn sub_noborrow(&mut self, other: &Self) {
self.0[0] = self.0[0].wrapping_sub(other.0[0]);
}
fn add_nocarry(&mut self, other: &Self) {
self.0[0] = self.0[0].wrapping_add(other.0[0]);
}
fn num_bits(&self) -> u32 {
64 - self.0[0].leading_zeros()
}
fn is_zero(&self) -> bool {
self.0[0] == 0
}
fn is_odd(&self) -> bool {
!self.is_even()
}
fn is_even(&self) -> bool {
self.0[0] % 2 == 0
}
fn div2(&mut self) {
self.shr(1)
}
fn shr(&mut self, amt: u32) {
self.0[0] >>= amt;
}
fn mul2(&mut self) {
self.shl(1)
}
fn shl(&mut self, amt: u32) {
self.0[0] <<= amt;
}
}
impl PrimeField for Fr {
type Repr = FrRepr;
const NUM_BITS: u32 = 16;
const CAPACITY: u32 = 15;
const S: u32 = 10;
fn from_repr(repr: FrRepr) -> Result<Self, PrimeFieldDecodingError> {
if repr.0[0] >= (MODULUS_R.0 as u64) {
Err(PrimeFieldDecodingError::NotInField(format!("{}", repr)))
} else {
Ok(Fr(Wrapping(repr.0[0] as u32)))
}
}
fn into_repr(&self) -> FrRepr {
FrRepr::from(*self)
}
fn char() -> FrRepr {
Fr(MODULUS_R).into()
}
fn multiplicative_generator() -> Fr {
Fr(Wrapping(5))
}
fn root_of_unity() -> Fr {
Fr(Wrapping(57751))
}
}
#[derive(Clone)]
pub struct DummyEngine;
impl Engine for DummyEngine {
type Fr = Fr;
type G1 = Fr;
type G1Affine = Fr;
type G2 = Fr;
type G2Affine = Fr;
type Fq = Fr;
type Fqe = Fr;
// TODO: This should be F_645131 or something. Doesn't matter for now.
type Fqk = Fr;
fn miller_loop<'a, I>(i: I) -> Self::Fqk
where I: IntoIterator<Item=&'a (
&'a <Self::G1Affine as CurveAffine>::Prepared,
&'a <Self::G2Affine as CurveAffine>::Prepared
)>
{
let mut acc = <Fr as Field>::zero();
for &(a, b) in i {
let mut tmp = *a;
<Fr as Field>::mul_assign(&mut tmp, b);
<Fr as Field>::add_assign(&mut acc, &tmp);
}
acc
}
/// Perform final exponentiation of the result of a miller loop.
fn final_exponentiation(this: &Self::Fqk) -> Option<Self::Fqk>
{
Some(*this)
}
}
impl CurveProjective for Fr {
type Affine = Fr;
type Base = Fr;
type Scalar = Fr;
type Engine = DummyEngine;
fn zero() -> Self {
<Fr as Field>::zero()
}
fn one() -> Self {
<Fr as Field>::one()
}
fn is_zero(&self) -> bool {
<Fr as Field>::is_zero(self)
}
fn batch_normalization(_: &mut [Self]) {
}
fn is_normalized(&self) -> bool {
true
}
fn double(&mut self) {
<Fr as Field>::double(self);
}
fn add_assign(&mut self, other: &Self) {
<Fr as Field>::add_assign(self, other);
}
fn add_assign_mixed(&mut self, other: &Self) {
<Fr as Field>::add_assign(self, other);
}
fn negate(&mut self) {
<Fr as Field>::negate(self);
}
fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S)
{
let tmp = Fr::from_repr(other.into()).unwrap();
<Fr as Field>::mul_assign(self, &tmp);
}
fn into_affine(&self) -> Fr {
*self
}
fn recommended_wnaf_for_scalar(_: <Self::Scalar as PrimeField>::Repr) -> usize {
3
}
fn recommended_wnaf_for_num_scalars(_: usize) -> usize {
3
}
}
#[derive(Copy, Clone)]
pub struct FakePoint;
impl AsMut<[u8]> for FakePoint {
fn as_mut(&mut self) -> &mut [u8] {
unimplemented!()
}
}
impl AsRef<[u8]> for FakePoint {
fn as_ref(&self) -> &[u8] {
unimplemented!()
}
}
impl EncodedPoint for FakePoint {
type Affine = Fr;
fn empty() -> Self {
unimplemented!()
}
fn size() -> usize {
unimplemented!()
}
fn into_affine(&self) -> Result<Self::Affine, GroupDecodingError> {
unimplemented!()
}
fn into_affine_unchecked(&self) -> Result<Self::Affine, GroupDecodingError> {
unimplemented!()
}
fn from_affine(_: Self::Affine) -> Self {
unimplemented!()
}
}
impl CurveAffine for Fr {
type Pair = Fr;
type PairingResult = Fr;
type Compressed = FakePoint;
type Uncompressed = FakePoint;
type Prepared = Fr;
type Projective = Fr;
type Base = Fr;
type Scalar = Fr;
type Engine = DummyEngine;
fn zero() -> Self {
<Fr as Field>::zero()
}
fn one() -> Self {
<Fr as Field>::one()
}
fn is_zero(&self) -> bool {
<Fr as Field>::is_zero(self)
}
fn negate(&mut self) {
<Fr as Field>::negate(self);
}
fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective
{
let mut res = *self;
let tmp = Fr::from_repr(other.into()).unwrap();
<Fr as Field>::mul_assign(&mut res, &tmp);
res
}
fn prepare(&self) -> Self::Prepared {
*self
}
fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult {
self.mul(*other)
}
fn into_projective(&self) -> Self::Projective {
*self
}
}
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use pairing::{
Engine,
Field,
PrimeField
};
mod dummy_engine;
use self::dummy_engine::*;
use std::marker::PhantomData;
use ::{
Circuit,
ConstraintSystem,
SynthesisError
};
use super::{
generate_parameters,
prepare_verifying_key,
create_proof,
verify_proof
};
struct XORDemo<E: Engine> {
a: Option<bool>,
b: Option<bool>,
_marker: PhantomData<E>
}
impl<E: Engine> Circuit<E> for XORDemo<E> {
fn synthesize<CS: ConstraintSystem<E>>(
self,
cs: &mut CS
) -> Result<(), SynthesisError>
{
let a_var = cs.alloc(|| "a", || {
if self.a.is_some() {
if self.a.unwrap() {
Ok(E::Fr::one())
} else {
Ok(E::Fr::zero())
}
} else {
Err(SynthesisError::AssignmentMissing)
}
})?;
cs.enforce(
|| "a_boolean_constraint",
|lc| lc + CS::one() - a_var,
|lc| lc + a_var,
|lc| lc
);
let b_var = cs.alloc(|| "b", || {
if self.b.is_some() {
if self.b.unwrap() {
Ok(E::Fr::one())
} else {
Ok(E::Fr::zero())
}
} else {
Err(SynthesisError::AssignmentMissing)
}
})?;
cs.enforce(
|| "b_boolean_constraint",
|lc| lc + CS::one() - b_var,
|lc| lc + b_var,
|lc| lc
);
let c_var = cs.alloc_input(|| "c", || {
if self.a.is_some() && self.b.is_some() {
if self.a.unwrap() ^ self.b.unwrap() {
Ok(E::Fr::one())
} else {
Ok(E::Fr::zero())
}
} else {
Err(SynthesisError::AssignmentMissing)
}
})?;
cs.enforce(
|| "c_xor_constraint",
|lc| lc + a_var + a_var,
|lc| lc + b_var,
|lc| lc + a_var + b_var - c_var
);
Ok(())
}
}
#[test]
fn test_xordemo() {
let g1 = Fr::one();
let g2 = Fr::one();
let alpha = Fr::from_str("48577").unwrap();
let beta = Fr::from_str("22580").unwrap();
let gamma = Fr::from_str("53332").unwrap();
let delta = Fr::from_str("5481").unwrap();
let tau = Fr::from_str("3673").unwrap();
let params = {
let c = XORDemo::<DummyEngine> {
a: None,
b: None,
_marker: PhantomData
};
generate_parameters(
c,
g1,
g2,
alpha,
beta,
gamma,
delta,
tau
).unwrap()
};
// This will synthesize the constraint system:
//
// public inputs: a_0 = 1, a_1 = c
// aux inputs: a_2 = a, a_3 = b
// constraints:
// (a_0 - a_2) * (a_2) = 0
// (a_0 - a_3) * (a_3) = 0
// (a_2 + a_2) * (a_3) = (a_2 + a_3 - a_1)
// (a_0) * 0 = 0
// (a_1) * 0 = 0
// The evaluation domain is 8. The H query should
// have 7 elements (it's a quotient polynomial)
assert_eq!(7, params.h.len());
let mut root_of_unity = Fr::root_of_unity();
// We expect this to be a 2^10 root of unity
assert_eq!(Fr::one(), root_of_unity.pow(&[1 << 10]));
// Let's turn it into a 2^3 root of unity.
root_of_unity = root_of_unity.pow(&[1 << 7]);
assert_eq!(Fr::one(), root_of_unity.pow(&[1 << 3]));
assert_eq!(Fr::from_str("20201").unwrap(), root_of_unity);
// Let's compute all the points in our evaluation domain.
let mut points = Vec::with_capacity(8);
for i in 0..8 {
points.push(root_of_unity.pow(&[i]));
}
// Let's compute t(tau) = (tau - p_0)(tau - p_1)...
// = tau^8 - 1
let mut t_at_tau = tau.pow(&[8]);
t_at_tau.sub_assign(&Fr::one());
{
let mut tmp = Fr::one();
for p in &points {
let mut term = tau;
term.sub_assign(p);
tmp.mul_assign(&term);
}
assert_eq!(tmp, t_at_tau);
}
// We expect our H query to be 7 elements of the form...
// {tau^i t(tau) / delta}
let delta_inverse = delta.inverse().unwrap();
let gamma_inverse = gamma.inverse().unwrap();
{
let mut coeff = delta_inverse;
coeff.mul_assign(&t_at_tau);
let mut cur = Fr::one();
for h in params.h.iter() {
let mut tmp = cur;
tmp.mul_assign(&coeff);
assert_eq!(*h, tmp);
cur.mul_assign(&tau);
}
}
// The density of the IC query is 2 (2 inputs)
assert_eq!(2, params.vk.ic.len());
// The density of the L query is 2 (2 aux variables)
assert_eq!(2, params.l.len());
// The density of the A query is 4 (each variable is in at least one A term)
assert_eq!(4, params.a.len());
// The density of the B query is 2 (two variables are in at least one B term)
assert_eq!(2, params.b_g1.len());
assert_eq!(2, params.b_g2.len());
/*
Lagrange interpolation polynomials in our evaluation domain:
,-------------------------------. ,-------------------------------. ,-------------------------------.
| A TERM | | B TERM | | C TERM |
`-------------------------------. `-------------------------------' `-------------------------------'
| a_0 | a_1 | a_2 | a_3 | | a_0 | a_1 | a_2 | a_3 | | a_0 | a_1 | a_2 | a_3 |
| 1 | 0 | 64512 | 0 | | 0 | 0 | 1 | 0 | | 0 | 0 | 0 | 0 |
| 1 | 0 | 0 | 64512 | | 0 | 0 | 0 | 1 | | 0 | 0 | 0 | 0 |
| 0 | 0 | 2 | 0 | | 0 | 0 | 0 | 1 | | 0 | 64512 | 1 | 1 |
| 1 | 0 | 0 | 0 | | 0 | 0 | 0 | 0 | | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 0 | | 0 | 0 | 0 | 0 | | 0 | 0 | 0 | 0 |
`-------'-------'-------'-------' `-------'-------'-------'-------' `-------'-------'-------'-------'
Example for u_0:
sage: r = 64513
sage: Fr = GF(r)
sage: omega = (Fr(5)^63)^(2^7)
sage: tau = Fr(3673)
sage: R.<x> = PolynomialRing(Fr, 'x')
sage: def eval(tau, c0, c1, c2, c3, c4):
....: p = R.lagrange_polynomial([(omega^0, c0), (omega^1, c1), (omega^2, c2), (omega^3, c3), (omega^4, c4), (omega^5, 0), (omega^6, 0), (omega^7, 0)])
....: return p.substitute(tau)
sage: eval(tau, 1, 1, 0, 1, 0)
59158
*/
let u_i = [59158, 48317, 21767, 10402].iter().map(|e| {
Fr::from_str(&format!("{}", e)).unwrap()
}).collect::<Vec<Fr>>();
let v_i = [0, 0, 60619, 30791].iter().map(|e| {
Fr::from_str(&format!("{}", e)).unwrap()
}).collect::<Vec<Fr>>();
let w_i = [0, 23320, 41193, 41193].iter().map(|e| {
Fr::from_str(&format!("{}", e)).unwrap()
}).collect::<Vec<Fr>>();
for (u, a) in u_i.iter()
.zip(&params.a[..])
{
assert_eq!(u, a);
}
for (v, b) in v_i.iter()
.filter(|&&e| e != Fr::zero())
.zip(&params.b_g1[..])
{
assert_eq!(v, b);
}
for (v, b) in v_i.iter()
.filter(|&&e| e != Fr::zero())
.zip(&params.b_g2[..])
{
assert_eq!(v, b);
}
for i in 0..4 {
let mut tmp1 = beta;
tmp1.mul_assign(&u_i[i]);
let mut tmp2 = alpha;
tmp2.mul_assign(&v_i[i]);
tmp1.add_assign(&tmp2);
tmp1.add_assign(&w_i[i]);
if i < 2 {
// Check the correctness of the IC query elements
tmp1.mul_assign(&gamma_inverse);
assert_eq!(tmp1, params.vk.ic[i]);
} else {
// Check the correctness of the L query elements
tmp1.mul_assign(&delta_inverse);
assert_eq!(tmp1, params.l[i - 2]);
}
}
// Check consistency of the other elements
assert_eq!(alpha, params.vk.alpha_g1);
assert_eq!(beta, params.vk.beta_g1);
assert_eq!(beta, params.vk.beta_g2);
assert_eq!(gamma, params.vk.gamma_g2);
assert_eq!(delta, params.vk.delta_g1);
assert_eq!(delta, params.vk.delta_g2);
let pvk = prepare_verifying_key(&params.vk);
let r = Fr::from_str("27134").unwrap();
let s = Fr::from_str("17146").unwrap();
let proof = {
let c = XORDemo {
a: Some(true),
b: Some(false),
_marker: PhantomData
};
create_proof(
c,
&params,
r,
s
).unwrap()
};
// A(x) =
// a_0 * (44865*x^7 + 56449*x^6 + 44865*x^5 + 8064*x^4 + 3520*x^3 + 56449*x^2 + 3520*x + 40321) +
// a_1 * (8064*x^7 + 56449*x^6 + 8064*x^5 + 56449*x^4 + 8064*x^3 + 56449*x^2 + 8064*x + 56449) +
// a_2 * (16983*x^7 + 24192*x^6 + 63658*x^5 + 56449*x^4 + 16983*x^3 + 24192*x^2 + 63658*x + 56449) +
// a_3 * (5539*x^7 + 27797*x^6 + 6045*x^5 + 56449*x^4 + 58974*x^3 + 36716*x^2 + 58468*x + 8064) +
{
// proof A = alpha + A(tau) + delta * r
let mut expected_a = delta;
expected_a.mul_assign(&r);
expected_a.add_assign(&alpha);
expected_a.add_assign(&u_i[0]); // a_0 = 1
expected_a.add_assign(&u_i[1]); // a_1 = 1
expected_a.add_assign(&u_i[2]); // a_2 = 1
// a_3 = 0
assert_eq!(proof.a, expected_a);
}
// B(x) =
// a_0 * (0) +
// a_1 * (0) +
// a_2 * (56449*x^7 + 56449*x^6 + 56449*x^5 + 56449*x^4 + 56449*x^3 + 56449*x^2 + 56449*x + 56449) +
// a_3 * (31177*x^7 + 44780*x^6 + 21752*x^5 + 42255*x^3 + 35861*x^2 + 33842*x + 48385)
{
// proof B = beta + B(tau) + delta * s
let mut expected_b = delta;
expected_b.mul_assign(&s);
expected_b.add_assign(&beta);
expected_b.add_assign(&v_i[0]); // a_0 = 1
expected_b.add_assign(&v_i[1]); // a_1 = 1
expected_b.add_assign(&v_i[2]); // a_2 = 1
// a_3 = 0
assert_eq!(proof.b, expected_b);
}
// C(x) =
// a_0 * (0) +
// a_1 * (27797*x^7 + 56449*x^6 + 36716*x^5 + 8064*x^4 + 27797*x^3 + 56449*x^2 + 36716*x + 8064) +
// a_2 * (36716*x^7 + 8064*x^6 + 27797*x^5 + 56449*x^4 + 36716*x^3 + 8064*x^2 + 27797*x + 56449) +
// a_3 * (36716*x^7 + 8064*x^6 + 27797*x^5 + 56449*x^4 + 36716*x^3 + 8064*x^2 + 27797*x + 56449)
//
// If A * B = C at each point in the domain, then the following polynomial...
// P(x) = A(x) * B(x) - C(x)
// = 49752*x^14 + 13914*x^13 + 29243*x^12 + 27227*x^11 + 62362*x^10 + 35703*x^9 + 4032*x^8 + 14761*x^6 + 50599*x^5 + 35270*x^4 + 37286*x^3 + 2151*x^2 + 28810*x + 60481
//
// ... should be divisible by t(x), producing the quotient polynomial:
// h(x) = P(x) / t(x)
// = 49752*x^6 + 13914*x^5 + 29243*x^4 + 27227*x^3 + 62362*x^2 + 35703*x + 4032
{
let mut expected_c = Fr::zero();
// A * s
let mut tmp = proof.a;
tmp.mul_assign(&s);
expected_c.add_assign(&tmp);
// B * r
let mut tmp = proof.b;
tmp.mul_assign(&r);
expected_c.add_assign(&tmp);
// delta * r * s
let mut tmp = delta;
tmp.mul_assign(&r);
tmp.mul_assign(&s);
expected_c.sub_assign(&tmp);
// L query answer
// a_2 = 1, a_3 = 0
expected_c.add_assign(&params.l[0]);
// H query answer
for (i, coeff) in [5040, 11763, 10755, 63633, 128, 9747, 8739].iter().enumerate() {
let coeff = Fr::from_str(&format!("{}", coeff)).unwrap();
let mut tmp = params.h[i];
tmp.mul_assign(&coeff);
expected_c.add_assign(&tmp);
}
assert_eq!(expected_c, proof.c);
}
assert!(verify_proof(
&pvk,
&proof,
&[Fr::one()]
).unwrap());
}
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@@ -0,0 +1,66 @@
use pairing::{
Engine,
CurveProjective,
CurveAffine,
PrimeField
};
use super::{
Proof,
VerifyingKey,
PreparedVerifyingKey
};
use ::{
SynthesisError
};
pub fn prepare_verifying_key<E: Engine>(
vk: &VerifyingKey<E>
) -> PreparedVerifyingKey<E>
{
let mut gamma = vk.gamma_g2;
gamma.negate();
let mut delta = vk.delta_g2;
delta.negate();
PreparedVerifyingKey {
alpha_g1_beta_g2: E::pairing(vk.alpha_g1, vk.beta_g2),
neg_gamma_g2: gamma.prepare(),
neg_delta_g2: delta.prepare(),
ic: vk.ic.clone()
}
}
pub fn verify_proof<'a, E: Engine>(
pvk: &'a PreparedVerifyingKey<E>,
proof: &Proof<E>,
public_inputs: &[E::Fr]
) -> Result<bool, SynthesisError>
{
if (public_inputs.len() + 1) != pvk.ic.len() {
return Err(SynthesisError::MalformedVerifyingKey);
}
let mut acc = pvk.ic[0].into_projective();
for (i, b) in public_inputs.iter().zip(pvk.ic.iter().skip(1)) {
acc.add_assign(&b.mul(i.into_repr()));
}
// The original verification equation is:
// A * B = alpha * beta + inputs * gamma + C * delta
// ... however, we rearrange it so that it is:
// A * B - inputs * gamma - C * delta = alpha * beta
// or equivalently:
// A * B + inputs * (-gamma) + C * (-delta) = alpha * beta
// which allows us to do a single final exponentiation.
Ok(E::final_exponentiation(
&E::miller_loop([
(&proof.a.prepare(), &proof.b.prepare()),
(&acc.into_affine().prepare(), &pvk.neg_gamma_g2),
(&proof.c.prepare(), &pvk.neg_delta_g2)
].into_iter())
).unwrap() == pvk.alpha_g1_beta_g2)
}