Merge pull request #246 from mir-protocol/goldilocks_ext

Goldilocks extension fields
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wborgeaud 2021-09-15 18:32:15 +02:00 committed by GitHub
commit b5d35b3582
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4 changed files with 154 additions and 170 deletions

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@ -201,82 +201,25 @@ impl<F: Extendable<2>> DivAssign for QuadraticExtension<F> {
#[cfg(test)]
mod tests {
use crate::field::crandall_field::CrandallField;
use crate::field::extension_field::quadratic::QuadraticExtension;
use crate::field::extension_field::Frobenius;
use crate::field::field_types::Field;
use crate::test_field_arithmetic;
mod crandall {
use crate::{test_field_arithmetic, test_field_extension};
#[test]
fn test_add_neg_sub_mul() {
type F = QuadraticExtension<CrandallField>;
let x = F::rand();
let y = F::rand();
let z = F::rand();
assert_eq!(x + (-x), F::ZERO);
assert_eq!(-x, F::ZERO - x);
assert_eq!(x + x, x * F::TWO);
assert_eq!(x * (-x), -x.square());
assert_eq!(x + y, y + x);
assert_eq!(x * y, y * x);
assert_eq!(x * (y * z), (x * y) * z);
assert_eq!(x - (y + z), (x - y) - z);
assert_eq!((x + y) - z, x + (y - z));
assert_eq!(x * (y + z), x * y + x * z);
}
#[test]
fn test_inv_div() {
type F = QuadraticExtension<CrandallField>;
let x = F::rand();
let y = F::rand();
let z = F::rand();
assert_eq!(x * x.inverse(), F::ONE);
assert_eq!(x.inverse() * x, F::ONE);
assert_eq!(x.square().inverse(), x.inverse().square());
assert_eq!((x / y) * y, x);
assert_eq!(x / (y * z), (x / y) / z);
assert_eq!((x * y) / z, x * (y / z));
}
#[test]
fn test_frobenius() {
type F = QuadraticExtension<CrandallField>;
let x = F::rand();
assert_eq!(x.exp_biguint(&CrandallField::order()), x.frobenius());
}
#[test]
fn test_field_order() {
// F::order() = 340282366831806780677557380898690695169 = 18446744071293632512 *18446744071293632514 + 1
type F = QuadraticExtension<CrandallField>;
let x = F::rand();
assert_eq!(
x.exp_u64(18446744071293632512)
.exp_u64(18446744071293632514),
F::ONE
test_field_extension!(crate::field::crandall_field::CrandallField, 2);
test_field_arithmetic!(
crate::field::extension_field::quadratic::QuadraticExtension<
crate::field::crandall_field::CrandallField,
>
);
}
#[test]
fn test_power_of_two_gen() {
type F = QuadraticExtension<CrandallField>;
// F::order() = 2^29 * 2762315674048163 * 229454332791453 + 1
assert_eq!(
F::MULTIPLICATIVE_GROUP_GENERATOR
.exp_u64(2762315674048163)
.exp_u64(229454332791453),
F::POWER_OF_TWO_GENERATOR
);
assert_eq!(
F::POWER_OF_TWO_GENERATOR.exp_u64(1 << (F::TWO_ADICITY - CrandallField::TWO_ADICITY)),
CrandallField::POWER_OF_TWO_GENERATOR.into()
mod goldilocks {
use crate::{test_field_arithmetic, test_field_extension};
test_field_extension!(crate::field::goldilocks_field::GoldilocksField, 2);
test_field_arithmetic!(
crate::field::extension_field::quadratic::QuadraticExtension<
crate::field::goldilocks_field::GoldilocksField,
>
);
}
test_field_arithmetic!(
crate::field::extension_field::quadratic::QuadraticExtension<
crate::field::crandall_field::CrandallField,
>
);
}

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@ -227,108 +227,25 @@ impl<F: Extendable<4>> DivAssign for QuarticExtension<F> {
#[cfg(test)]
mod tests {
use crate::field::crandall_field::CrandallField;
use crate::field::extension_field::quartic::QuarticExtension;
use crate::field::extension_field::Frobenius;
use crate::field::field_types::Field;
use crate::test_field_arithmetic;
mod crandall {
use crate::{test_field_arithmetic, test_field_extension};
fn exp_naive<F: Field>(x: F, power: u128) -> F {
let mut current = x;
let mut product = F::ONE;
for j in 0..128 {
if (power >> j & 1) != 0 {
product *= current;
}
current = current.square();
}
product
}
#[test]
fn test_add_neg_sub_mul() {
type F = QuarticExtension<CrandallField>;
let x = F::rand();
let y = F::rand();
let z = F::rand();
assert_eq!(x + (-x), F::ZERO);
assert_eq!(-x, F::ZERO - x);
assert_eq!(x + x, x * F::TWO.into());
assert_eq!(x * (-x), -x.square());
assert_eq!(x + y, y + x);
assert_eq!(x * y, y * x);
assert_eq!(x * (y * z), (x * y) * z);
assert_eq!(x - (y + z), (x - y) - z);
assert_eq!((x + y) - z, x + (y - z));
assert_eq!(x * (y + z), x * y + x * z);
}
#[test]
fn test_inv_div() {
type F = QuarticExtension<CrandallField>;
let x = F::rand();
let y = F::rand();
let z = F::rand();
assert_eq!(x * x.inverse(), F::ONE);
assert_eq!(x.inverse() * x, F::ONE);
assert_eq!(x.square().inverse(), x.inverse().square());
assert_eq!((x / y) * y, x);
assert_eq!(x / (y * z), (x / y) / z);
assert_eq!((x * y) / z, x * (y / z));
}
#[test]
fn test_frobenius() {
type F = QuarticExtension<CrandallField>;
const D: usize = 4;
let x = F::rand();
assert_eq!(x.exp_biguint(&CrandallField::order()), x.frobenius());
for count in 2..D {
assert_eq!(
x.repeated_frobenius(count),
(0..count).fold(x, |acc, _| acc.frobenius())
);
}
}
#[test]
fn test_field_order() {
// F::order() = 340282366831806780677557380898690695168 * 340282366831806780677557380898690695170 + 1
type F = QuarticExtension<CrandallField>;
let x = F::rand();
assert_eq!(
exp_naive(
exp_naive(x, 340282366831806780677557380898690695168),
340282366831806780677557380898690695170
),
F::ONE
test_field_extension!(crate::field::crandall_field::CrandallField, 4);
test_field_arithmetic!(
crate::field::extension_field::quartic::QuarticExtension<
crate::field::crandall_field::CrandallField,
>
);
}
#[test]
fn test_power_of_two_gen() {
type F = QuarticExtension<CrandallField>;
// F::order() = 2^30 * 1090552343587053358839971118999869 * 98885475095492590491252558464653635 + 1
assert_eq!(
exp_naive(
exp_naive(
F::MULTIPLICATIVE_GROUP_GENERATOR,
1090552343587053358839971118999869
),
98885475095492590491252558464653635
),
F::POWER_OF_TWO_GENERATOR
);
assert_eq!(
F::POWER_OF_TWO_GENERATOR.exp_u64(1 << (F::TWO_ADICITY - CrandallField::TWO_ADICITY)),
CrandallField::POWER_OF_TWO_GENERATOR.into()
mod goldilocks {
use crate::{test_field_arithmetic, test_field_extension};
test_field_extension!(crate::field::goldilocks_field::GoldilocksField, 4);
test_field_arithmetic!(
crate::field::extension_field::quartic::QuarticExtension<
crate::field::goldilocks_field::GoldilocksField,
>
);
}
test_field_arithmetic!(
crate::field::extension_field::quartic::QuarticExtension<
crate::field::crandall_field::CrandallField,
>
);
}

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@ -1,3 +1,7 @@
use crate::field::extension_field::Extendable;
use crate::field::extension_field::Frobenius;
use crate::field::field_types::Field;
#[macro_export]
macro_rules! test_field_arithmetic {
($field:ty) => {
@ -93,3 +97,91 @@ macro_rules! test_field_arithmetic {
}
};
}
pub(crate) fn test_add_neg_sub_mul<BF: Extendable<D>, const D: usize>() {
let x = BF::Extension::rand();
let y = BF::Extension::rand();
let z = BF::Extension::rand();
assert_eq!(x + (-x), BF::Extension::ZERO);
assert_eq!(-x, BF::Extension::ZERO - x);
assert_eq!(x + x, x * BF::Extension::TWO);
assert_eq!(x * (-x), -x.square());
assert_eq!(x + y, y + x);
assert_eq!(x * y, y * x);
assert_eq!(x * (y * z), (x * y) * z);
assert_eq!(x - (y + z), (x - y) - z);
assert_eq!((x + y) - z, x + (y - z));
assert_eq!(x * (y + z), x * y + x * z);
}
pub(crate) fn test_inv_div<BF: Extendable<D>, const D: usize>() {
let x = BF::Extension::rand();
let y = BF::Extension::rand();
let z = BF::Extension::rand();
assert_eq!(x * x.inverse(), BF::Extension::ONE);
assert_eq!(x.inverse() * x, BF::Extension::ONE);
assert_eq!(x.square().inverse(), x.inverse().square());
assert_eq!((x / y) * y, x);
assert_eq!(x / (y * z), (x / y) / z);
assert_eq!((x * y) / z, x * (y / z));
}
pub(crate) fn test_frobenius<BF: Extendable<D>, const D: usize>() {
let x = BF::Extension::rand();
assert_eq!(x.exp_biguint(&BF::order()), x.frobenius());
for count in 2..D {
assert_eq!(
x.repeated_frobenius(count),
(0..count).fold(x, |acc, _| acc.frobenius())
);
}
}
pub(crate) fn test_field_order<BF: Extendable<D>, const D: usize>() {
let x = BF::Extension::rand();
assert_eq!(
x.exp_biguint(&(BF::Extension::order() - 1u8)),
BF::Extension::ONE
);
}
pub(crate) fn test_power_of_two_gen<BF: Extendable<D>, const D: usize>() {
assert_eq!(
BF::Extension::MULTIPLICATIVE_GROUP_GENERATOR
.exp_biguint(&(BF::Extension::order() >> BF::Extension::TWO_ADICITY)),
BF::Extension::POWER_OF_TWO_GENERATOR,
);
assert_eq!(
BF::Extension::POWER_OF_TWO_GENERATOR
.exp_u64(1 << (BF::Extension::TWO_ADICITY - BF::TWO_ADICITY)),
BF::POWER_OF_TWO_GENERATOR.into()
);
}
#[macro_export]
macro_rules! test_field_extension {
($field:ty, $d:expr) => {
mod field_extension {
#[test]
fn test_add_neg_sub_mul() {
crate::field::field_testing::test_add_neg_sub_mul::<$field, $d>();
}
#[test]
fn test_inv_div() {
crate::field::field_testing::test_inv_div::<$field, $d>();
}
#[test]
fn test_frobenius() {
crate::field::field_testing::test_frobenius::<$field, $d>();
}
#[test]
fn test_field_order() {
crate::field::field_testing::test_field_order::<$field, $d>();
}
#[test]
fn test_power_of_two_gen() {
crate::field::field_testing::test_power_of_two_gen::<$field, $d>();
}
}
};
}

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@ -8,6 +8,9 @@ use num::BigUint;
use rand::Rng;
use serde::{Deserialize, Serialize};
use crate::field::extension_field::quadratic::QuadraticExtension;
use crate::field::extension_field::quartic::QuarticExtension;
use crate::field::extension_field::Extendable;
use crate::field::field_types::{Field, PrimeField};
use crate::field::inversion::try_inverse_u64;
@ -213,6 +216,35 @@ impl DivAssign for GoldilocksField {
}
}
impl Extendable<2> for GoldilocksField {
type Extension = QuadraticExtension<Self>;
// Verifiable in Sage with
// `R.<x> = GF(p)[]; assert (x^2 - 7).is_irreducible()`.
const W: Self = Self(7);
const EXT_MULTIPLICATIVE_GROUP_GENERATOR: [Self; 2] =
[Self(18081566051660590251), Self(16121475356294670766)];
const EXT_POWER_OF_TWO_GENERATOR: [Self; 2] = [Self(0), Self(15659105665374529263)];
}
impl Extendable<4> for GoldilocksField {
type Extension = QuarticExtension<Self>;
const W: Self = Self(7);
const EXT_MULTIPLICATIVE_GROUP_GENERATOR: [Self; 4] = [
Self(5024755240244648895),
Self(13227474371289740625),
Self(3912887029498544536),
Self(3900057112666848848),
];
const EXT_POWER_OF_TWO_GENERATOR: [Self; 4] =
[Self(0), Self(0), Self(0), Self(12587610116473453104)];
}
/// Reduces to a 64-bit value. The result might not be in canonical form; it could be in between the
/// field order and `2^64`.
#[inline]