rewrite w methods

This commit is contained in:
Dmitry Vagner 2023-01-24 00:01:47 +07:00
parent ec4cddb7c9
commit 75c5938c49
3 changed files with 227 additions and 223 deletions

View File

@ -64,12 +64,18 @@ impl Mul for Fp {
}
}
impl Fp {
pub fn inv(self) -> Fp {
exp_fp(self, BN_BASE - 2)
}
}
#[allow(clippy::suspicious_arithmetic_impl)]
impl Div for Fp {
type Output = Self;
fn div(self, rhs: Self) -> Self::Output {
let inv = exp_fp(rhs, BN_BASE - 2);
self * inv
self * rhs.inv()
}
}
@ -97,6 +103,16 @@ pub struct Fp2 {
pub im: Fp,
}
pub const ZERO_FP2: Fp2 = Fp2 {
re: ZERO_FP,
im: ZERO_FP,
};
pub const UNIT_FP2: Fp2 = Fp2 {
re: UNIT_FP,
im: ZERO_FP,
};
impl Add for Fp2 {
type Output = Self;
@ -141,61 +157,58 @@ impl Mul for Fp2 {
}
}
/// The inverse of z is given by z'/||z|| since ||z|| = zz'
impl Fp2 {
/// We preemptively define a helper function which multiplies an Fp2 element by 9 + i
fn i9(self) -> Fp2 {
let nine = Fp::new(9);
Fp2 {
re: nine * self.re - self.im,
im: self.re + nine * self.im,
}
}
pub fn scale(self, x: Fp) -> Fp2 {
Fp2 {
re: x * self.re,
im: x * self.im,
}
}
// This function takes the complex conjugate
fn conj(self) -> Fp2 {
Fp2 {
re: self.re,
im: -self.im,
}
}
// Return the magnitude of the complex number
fn norm(self) -> Fp {
self.re * self.re + self.im * self.im
}
// This function normalizes the input to the complex unit circle
fn normalize(self) -> Fp2 {
let norm = self.norm();
self.scale(UNIT_FP / norm)
}
/// The inverse of z is given by z'/||z|| since ||z|| = zz'
pub fn inv(self) -> Fp2 {
let norm = self.re * self.re + self.im * self.im;
self.conj().scale(norm)
}
}
#[allow(clippy::suspicious_arithmetic_impl)]
impl Div for Fp2 {
type Output = Self;
fn div(self, rhs: Self) -> Self::Output {
let norm = rhs.re * rhs.re + rhs.im * rhs.im;
let inv = scalar_mul_fp2(norm, conj_fp2(rhs));
self * inv
}
}
pub const ZERO_FP2: Fp2 = Fp2 {
re: ZERO_FP,
im: ZERO_FP,
};
pub const UNIT_FP2: Fp2 = Fp2 {
re: UNIT_FP,
im: ZERO_FP,
};
pub fn scalar_mul_fp2(x: Fp, a: Fp2) -> Fp2 {
Fp2 {
re: x * a.re,
im: x * a.im,
}
}
// This function takes the complex conjugate
fn conj_fp2(a: Fp2) -> Fp2 {
Fp2 {
re: a.re,
im: -a.im,
}
}
// This function normalizes the input to the complex unit circle
fn normalize_fp2(a: Fp2) -> Fp2 {
let norm = a.re * a.re + a.im * a.im;
Fp2 {
re: a.re / norm,
im: a.im / norm,
self * rhs.inv()
}
}
/// The degree 3 field extension Fp6 over Fp2 is given by adjoining t, where t^3 = 9 + i
/// We begin by defining a helper function which multiplies an Fp2 element by 9 + i
fn i9(a: Fp2) -> Fp2 {
let nine = Fp::new(9);
Fp2 {
re: nine * a.re - a.im,
im: a.re + nine * a.im,
}
}
// Fp6 has basis 1, t, t^2 over Fp2
#[derive(Debug, Copy, Clone, PartialEq)]
pub struct Fp6 {
@ -204,6 +217,18 @@ pub struct Fp6 {
pub t2: Fp2,
}
pub const ZERO_FP6: Fp6 = Fp6 {
t0: ZERO_FP2,
t1: ZERO_FP2,
t2: ZERO_FP2,
};
pub const UNIT_FP6: Fp6 = Fp6 {
t0: UNIT_FP2,
t1: ZERO_FP2,
t2: ZERO_FP2,
};
impl Add for Fp6 {
type Output = Self;
@ -245,66 +270,89 @@ impl Mul for Fp6 {
fn mul(self, other: Self) -> Self {
Fp6 {
t0: self.t0 * other.t0 + i9(self.t1 * other.t2 + self.t2 * other.t1),
t1: self.t0 * other.t1 + self.t1 * other.t0 + i9(self.t2 * other.t2),
t0: self.t0 * other.t0 + (self.t1 * other.t2 + self.t2 * other.t1).i9(),
t1: self.t0 * other.t1 + self.t1 * other.t0 + (self.t2 * other.t2).i9(),
t2: self.t0 * other.t2 + self.t1 * other.t1 + self.t2 * other.t0,
}
}
}
/// Let x_n = x^(p^n) and note that
/// x_0 = x^(p^0) = x^1 = x
/// (x_n)_m = (x^(p^n))^(p^m) = x^(p^n * p^m) = x^(p^(n+m)) = x_{n+m}
/// By Galois Theory, given x: Fp6, the product
/// phi = x_0 * x_1 * x_2 * x_3 * x_4 * x_5
/// lands in Fp, and hence the inverse of x is given by
/// (x_1 * x_2 * x_3 * x_4 * x_5) / phi
/// We can save compute by rearranging the numerator:
/// (x_1 * x_3) * x_5 * (x_1 * x_3)_1
/// By Galois theory, the following are in Fp2 and are complex conjugates
/// x_1 * x_3 * x_5, x_0 * x_2 * x_4
/// Thus phi = norm(x_1 * x_3 * x_5), and hence the inverse is given by
/// normalize([x_1 * x_3] * x_5) * [x_1 * x_3]_1
impl Fp6 {
fn scale(self, x: Fp2) -> Fp6 {
Fp6 {
t0: x * self.t0,
t1: x * self.t1,
t2: x * self.t2,
}
}
/// This function multiplies an Fp6 element by t, and hence shifts the bases,
/// where the t^2 coefficient picks up a factor of 9+i as the 1 coefficient of the output
fn sh(self) -> Fp6 {
Fp6 {
t0: self.t2.i9(),
t1: self.t0,
t2: self.t1,
}
}
/// The nth frobenius endomorphism of a p^q field is given by mapping
/// x to x^(p^n)
/// which sends a + bt + ct^2: Fp6 to
/// a^(p^n) + b^(p^n) * t^(p^n) + c^(p^n) * t^(2p^n)
/// Note that p == 3 mod 4, and i^3 = -i, so x + yi gets mapped to
/// (x + yi)^(p^n) = x^(p^n) + y^(p^n) i^(p^n) = x + y i^(p^n mod 4)
/// which reduces to x + yi for n even and x - yi for n odd
/// The values of t^(p^n) and t^(2p^n) are precomputed in
/// the constant arrays FROB_T1 and FROB_T2
fn frob(self, n: usize) -> Fp6 {
let n = n % 6;
let frob_t1 = FROB_T1[n];
let frob_t2 = FROB_T2[n];
if n % 2 != 0 {
Fp6 {
t0: self.t0.conj(),
t1: frob_t1 * self.t1.conj(),
t2: frob_t2 * self.t2.conj(),
}
} else {
Fp6 {
t0: self.t0,
t1: frob_t1 * self.t1,
t2: frob_t2 * self.t2,
}
}
}
/// Let x_n = x^(p^n) and note that
/// x_0 = x^(p^0) = x^1 = x
/// (x_n)_m = (x^(p^n))^(p^m) = x^(p^n * p^m) = x^(p^(n+m)) = x_{n+m}
/// By Galois Theory, given x: Fp6, the product
/// phi = x_0 * x_1 * x_2 * x_3 * x_4 * x_5
/// lands in Fp, and hence the inverse of x is given by
/// (x_1 * x_2 * x_3 * x_4 * x_5) / phi
/// We can save compute by rearranging the numerator:
/// (x_1 * x_3) * x_5 * (x_1 * x_3)_1
/// By Galois theory, the following are in Fp2 and are complex conjugates
/// x_1 * x_3 * x_5, x_0 * x_2 * x_4
/// Thus phi = norm(x_1 * x_3 * x_5), and hence the inverse is given by
/// normalize([x_1 * x_3] * x_5) * [x_1 * x_3]_1
pub fn inv(self) -> Fp6 {
let prod_13 = self.frob(1) * self.frob(3);
let prod_135 = (prod_13 * self.frob(5)).t0;
let prod_odds_over_phi = prod_135.normalize();
let prod_24 = prod_13.frob(1);
prod_24.scale(prod_odds_over_phi)
}
}
#[allow(clippy::suspicious_arithmetic_impl)]
impl Div for Fp6 {
type Output = Self;
fn div(self, rhs: Self) -> Self::Output {
let prod_13 = frob_fp6(1, rhs) * frob_fp6(3, rhs);
let prod_135 = (prod_13 * frob_fp6(5, rhs)).t0;
let prod_odds_over_phi = normalize_fp2(prod_135);
let prod_24 = frob_fp6(1, prod_13);
let inv = scalar_mul_fp6(prod_odds_over_phi, prod_24);
self * inv
}
}
pub const ZERO_FP6: Fp6 = Fp6 {
t0: ZERO_FP2,
t1: ZERO_FP2,
t2: ZERO_FP2,
};
pub const UNIT_FP6: Fp6 = Fp6 {
t0: UNIT_FP2,
t1: ZERO_FP2,
t2: ZERO_FP2,
};
fn scalar_mul_fp6(x: Fp2, f: Fp6) -> Fp6 {
Fp6 {
t0: x * f.t0,
t1: x * f.t1,
t2: x * f.t2,
}
}
/// This function multiplies an Fp6 element by t, and hence shifts the bases,
/// where the t^2 coefficient picks up a factor of 9+i as the 1 coefficient of the output
fn sh(c: Fp6) -> Fp6 {
Fp6 {
t0: i9(c.t2),
t1: c.t0,
t2: c.t1,
self * rhs.inv()
}
}
@ -316,6 +364,11 @@ pub struct Fp12 {
pub z1: Fp6,
}
pub const UNIT_FP12: Fp12 = Fp12 {
z0: UNIT_FP6,
z1: ZERO_FP6,
};
impl Mul for Fp12 {
type Output = Self;
@ -324,107 +377,69 @@ impl Mul for Fp12 {
let h1 = self.z1 * other.z1;
let h01 = (self.z0 + self.z1) * (other.z0 + other.z1);
Fp12 {
z0: h0 + sh(h1),
z0: h0 + h1.sh(),
z1: h01 - (h0 + h1),
}
}
}
/// By Galois Theory, given x: Fp12, the product
/// phi = Prod_{i=0}^11 x_i
/// lands in Fp, and hence the inverse of x is given by
/// (Prod_{i=1}^11 x_i) / phi
/// The 6th Frob map is nontrivial but leaves Fp6 fixed and hence must be the conjugate:
/// x_6 = (a + bz)_6 = a - bz = conj_fp12(x)
/// Letting prod_17 = x_1 * x_7, the remaining factors in the numerator can be expresed as:
/// [(prod_17) * (prod_17)_2] * (prod_17)_4 * [(prod_17) * (prod_17)_2]_1
/// By Galois theory, both the following are in Fp2 and are complex conjugates
/// prod_odds, prod_evens
/// Thus phi = norm(prod_odds), and hence the inverse is given by
/// normalize(prod_odds) * prod_evens_except_six * conj_fp12(x)
impl Fp12 {
fn conj(self) -> Fp12 {
Fp12 {
z0: self.z0,
z1: -self.z1,
}
}
fn scale(self, x: Fp6) -> Fp12 {
Fp12 {
z0: x * self.z0,
z1: x * self.z1,
}
}
/// The nth frobenius endomorphism of a p^q field is given by mapping
/// x to x^(p^n)
/// which sends a + bz: Fp12 to
/// a^(p^n) + b^(p^n) * z^(p^n)
/// where the values of z^(p^n) are precomputed in the constant array FROB_Z
pub fn frob(self, n: usize) -> Fp12 {
let n = n % 12;
Fp12 {
z0: self.z0.frob(n),
z1: self.z1.frob(n).scale(FROB_Z[n]),
}
}
/// By Galois Theory, given x: Fp12, the product
/// phi = Prod_{i=0}^11 x_i
/// lands in Fp, and hence the inverse of x is given by
/// (Prod_{i=1}^11 x_i) / phi
/// The 6th Frob map is nontrivial but leaves Fp6 fixed and hence must be the conjugate:
/// x_6 = (a + bz)_6 = a - bz = conj_fp12(x)
/// Letting prod_17 = x_1 * x_7, the remaining factors in the numerator can be expresed as:
/// [(prod_17) * (prod_17)_2] * (prod_17)_4 * [(prod_17) * (prod_17)_2]_1
/// By Galois theory, both the following are in Fp2 and are complex conjugates
/// prod_odds, prod_evens
/// Thus phi = norm(prod_odds), and hence the inverse is given by
/// normalize(prod_odds) * prod_evens_except_six * conj_fp12(x)
pub fn inv(self) -> Fp12 {
let prod_17 = (self.frob(1) * self.frob(7)).z0;
let prod_1379 = prod_17 * prod_17.frob(2);
let prod_odds = (prod_1379 * prod_17.frob(4)).t0;
let prod_odds_over_phi = prod_odds.normalize();
let prod_evens_except_six = prod_1379.frob(1);
let prod_penultimate = prod_evens_except_six.scale(prod_odds_over_phi);
self.conj().scale(prod_penultimate)
}
}
#[allow(clippy::suspicious_arithmetic_impl)]
impl Div for Fp12 {
type Output = Self;
fn div(self, rhs: Self) -> Self::Output {
let prod_17 = (frob_fp12(1, rhs) * frob_fp12(7, rhs)).z0;
let prod_1379 = prod_17 * frob_fp6(2, prod_17);
let prod_odds = (prod_1379 * frob_fp6(4, prod_17)).t0;
let prod_odds_over_phi = normalize_fp2(prod_odds);
let prod_evens_except_six = frob_fp6(1, prod_1379);
let prod_penultimate = scalar_mul_fp6(prod_odds_over_phi, prod_evens_except_six);
let inv = scalar_mul_fp12(prod_penultimate, conj_fp12(rhs));
self * inv
}
}
pub const UNIT_FP12: Fp12 = Fp12 {
z0: UNIT_FP6,
z1: ZERO_FP6,
};
fn conj_fp12(f: Fp12) -> Fp12 {
Fp12 {
z0: f.z0,
z1: -f.z1,
}
}
fn scalar_mul_fp12(c: Fp6, f: Fp12) -> Fp12 {
Fp12 {
z0: c * f.z0,
z1: c * f.z1,
}
}
impl Fp12 {
pub fn inv(self) -> Fp12 {
UNIT_FP12 / self
}
}
/// The nth frobenius endomorphism of a finite field F of order p^q is given by sending x: F to x^(p^n)
/// since any element x: F satisfies x^(p^q) = x = x^(p^0), these endomorphisms cycle modulo q
///
/// Thus in the case of Fp, there are no nontrivial such endomorphisms since x^p = x.
///
/// In the case of Fp2, the first and only nontrivial frobenius map sends a + bi to its complex conjugate:
/// a^p + b^p(i^p) = a - bi
/// since p == 3 mod 4, and i^3 = -i
///
/// An Fp6 element a + bt + ct^2 is sent to
/// a^(p^n) + b^(p^n) * t^(p^n) + c^(p^n) * t^(2p^n)
/// where the values of t^(p^n) and t^(2p^n) are precomputed in the constant arrays FROB_T1 and FROB_T2
///
///
/// An Fp12 element a + bz is sent to
/// a^(p^n) + b^(p^n) * z^(p^n)
/// where the values of z^(p^n) are precomputed in the constant array FROB_Z
fn frob_fp6(n: usize, c: Fp6) -> Fp6 {
let n = n % 6;
let frob_t1 = FROB_T1[n];
let frob_t2 = FROB_T2[n];
if n % 2 != 0 {
Fp6 {
t0: conj_fp2(c.t0),
t1: frob_t1 * conj_fp2(c.t1),
t2: frob_t2 * conj_fp2(c.t2),
}
} else {
Fp6 {
t0: c.t0,
t1: frob_t1 * c.t1,
t2: frob_t2 * c.t2,
}
}
}
pub fn frob_fp12(n: usize, f: Fp12) -> Fp12 {
let n = n % 12;
Fp12 {
z0: frob_fp6(n, f.z0),
z1: scalar_mul_fp6(FROB_Z[n], frob_fp6(n, f.z1)),
self * rhs.inv()
}
}
@ -523,7 +538,7 @@ const FROB_T2: [Fp2; 6] = [
0x848a1f55921ea762,
0xd33365f7be94ec72,
0x80f3c0b75a181e84,
0x5b54f5e64eea801,
0x05b54f5e64eea801,
]),
}
},
@ -737,7 +752,7 @@ const FROB_Z: [Fp2; 12] = [
0x71c39bb757899a9b,
0x2307d819d98302a7,
0x121dc8b86f6c4ccf,
0xbfab77f2c36b843,
0x0bfab77f2c36b843,
]),
}
},

View File

@ -2,9 +2,7 @@ use std::ops::Add;
use ethereum_types::U256;
use crate::bn254_arithmetic::{
frob_fp12, scalar_mul_fp2, Fp, Fp6, Fp12, Fp2, UNIT_FP12, ZERO_FP, ZERO_FP2, gen_fp, gen_fp2
};
use crate::bn254_arithmetic::{gen_fp, gen_fp2, Fp, Fp12, Fp2, Fp6, UNIT_FP12, ZERO_FP, ZERO_FP2};
// The curve consists of pairs (x, y): (Fp, Fp) | y^2 = x^3 + 2
#[derive(Debug, Copy, Clone, PartialEq)]
@ -103,24 +101,16 @@ pub fn sparse_embed(g000: Fp, g01: Fp2, g11: Fp2) -> Fp12 {
pub fn tangent(p: Curve, q: TwistedCurve) -> Fp12 {
let cx = -Fp::new(3) * p.x * p.x;
let cy = Fp::new(2) * p.y;
sparse_embed(
p.y * p.y - Fp::new(9),
scalar_mul_fp2(cx, q.x),
scalar_mul_fp2(cy, q.y),
)
sparse_embed(p.y * p.y - Fp::new(9), q.x.scale(cx), q.y.scale(cy))
}
pub fn cord(p1: Curve, p2: Curve, q: TwistedCurve) -> Fp12 {
let cx = p2.y - p1.y;
let cy = p1.x - p2.x;
sparse_embed(
p1.y * p2.x - p2.y * p1.x,
scalar_mul_fp2(cx, q.x),
scalar_mul_fp2(cy, q.y),
)
sparse_embed(p1.y * p2.x - p2.y * p1.x, q.x.scale(cx), q.y.scale(cy))
}
/// The output T of the miller loop is not an invariant,
/// The output T of the miller loop is not an invariant,
/// but one gets an invariant by raising T to the power
/// (p^12 - 1)/N = (p^6 - 1)(p^2 + 1)(p^4 - p^2 + 1)/N
/// where N is the cyclic group order of the curve.
@ -133,15 +123,14 @@ pub fn cord(p1: Curve, p2: Curve, q: TwistedCurve) -> Fp12 {
/// where 0 < a0, a1, a2 < p. Then the final power is given by
/// T = T_3 * (T^a2)_2 * (T^-a1)_1 * (T^-a0)
pub fn invariance_inducing_power(f: Fp12) -> Fp12 {
let mut t = frob_fp12(6, f) / f;
t = frob_fp12(2, t) * t;
let mut t = f.frob(6) / f;
t = t.frob(2) * t;
let (t_a2, t_a1, t_a0) = get_powers(t);
frob_fp12(3, t) * frob_fp12(2, t_a2) * frob_fp12(1, t_a1) * t_a0
t.frob(3) * t_a2.frob(2) * t_a1.frob(1) * t_a0
}
/// Given an f: Fp12, this function computes the triple
/// T^a2, T^(-a1), T^(-a0)
///
fn get_powers(f: Fp12) -> (Fp12, Fp12, Fp12) {
const EXPS4: [(usize, usize, usize); 64] = [
(1, 1, 0),

View File

@ -4,21 +4,21 @@ use std::ops::Range;
use anyhow::Result;
use ethereum_types::U256;
use crate::bn254_arithmetic::{frob_fp12, gen_fp12, Fp12};
use crate::bn254_pairing::{gen_fp12_sparse};
use crate::bn254_arithmetic::{gen_fp12, Fp12};
use crate::bn254_pairing::gen_fp12_sparse;
use crate::cpu::kernel::aggregator::KERNEL;
use crate::cpu::kernel::interpreter::Interpreter;
use crate::memory::segments::Segment;
use crate::witness::memory::MemoryAddress;
struct InterpreterSetup {
offset: String,
label: String,
stack: Vec<U256>,
memory: Vec<(usize, Vec<U256>)>,
}
fn run_setup_interpreter(setup: InterpreterSetup) -> Result<Interpreter<'static>> {
let label = KERNEL.global_labels[&setup.offset];
let label = KERNEL.global_labels[&setup.label];
let mut stack = setup.stack;
stack.reverse();
let mut interpreter = Interpreter::new_with_kernel(label, stack);
@ -61,7 +61,7 @@ fn setup_mul_test(
label: &str,
) -> InterpreterSetup {
InterpreterSetup {
offset: label.to_string(),
label: label.to_string(),
stack: vec![
U256::from(in0),
U256::from(in1),
@ -107,7 +107,7 @@ fn test_mul_fp12() -> Result<()> {
fn setup_frob_test(ptr: usize, f: Fp12, label: &str) -> InterpreterSetup {
InterpreterSetup {
offset: label.to_string(),
label: label.to_string(),
stack: vec![U256::from(ptr)],
memory: vec![(ptr, fp12_on_stack(f))],
}
@ -133,10 +133,10 @@ fn test_frob_fp12() -> Result<()> {
let out_frob_3: Vec<U256> = extract_kernel_output(ptr..ptr + 12, intrptr_frob_3);
let out_frob_6: Vec<U256> = extract_kernel_output(ptr..ptr + 12, intrptr_frob_6);
let exp_frob_1: Vec<U256> = fp12_on_stack(frob_fp12(1, f));
let exp_frob_2: Vec<U256> = fp12_on_stack(frob_fp12(2, f));
let exp_frob_3: Vec<U256> = fp12_on_stack(frob_fp12(3, f));
let exp_frob_6: Vec<U256> = fp12_on_stack(frob_fp12(6, f));
let exp_frob_1: Vec<U256> = fp12_on_stack(f.frob(1));
let exp_frob_2: Vec<U256> = fp12_on_stack(f.frob(2));
let exp_frob_3: Vec<U256> = fp12_on_stack(f.frob(3));
let exp_frob_6: Vec<U256> = fp12_on_stack(f.frob(6));
assert_eq!(out_frob_1, exp_frob_1);
assert_eq!(out_frob_2, exp_frob_2);
@ -153,7 +153,7 @@ fn test_inv_fp12() -> Result<()> {
let f: Fp12 = gen_fp12();
let setup = InterpreterSetup {
offset: "inv_fp12".to_string(),
label: "inv_fp12".to_string(),
stack: vec![U256::from(ptr), U256::from(inv), U256::from(0xdeadbeefu32)],
memory: vec![(ptr, fp12_on_stack(f))],
};