curves: Second curve group and some test (#49)

* chore: tests + scalar multiplication * fmt * wip: compiles, but generator point is broken * wip * fix mul, generator and add hardcoded tests (#51) * fix mul, generator and add hardcoded tests * fix generator test * wip * fix: test fails when rng has no inverse --------- Co-authored-by: Sambhav <[email protected]>
pluto · May 9, 2024 · 2637594 · 2637594
1 parent def9371
commit 2637594
Show file tree

Hide file tree

Showing 9 changed files with 495 additions and 72 deletions.
diff --git a/math/field.sage b/math/field.sage
@@ -54,8 +54,8 @@ F_2 = GF(101 ^ 2, name="t", modulus=P)
 print("extension field:", F_2, "of order:", F_2.order())
 
 # Primitive element
-f_2_primitive_element = F_2.primitive_element()
-print("Primitive element of F_2:", f_2_primitive_element, f_2_primitive_element.order())
+f_2_primitive_element = F_2([2, 1])
+print("Primitive element of F_2:", f_2_primitive_element, f_2_primitive_element.multiplicative_order())
 
 # 100th root of unity
 F_2_order = F_2.order()
@@ -65,5 +65,4 @@ quotient = (F_2_order-1)//root_of_unity_order
 f_2_omega_n = f_2_primitive_element ^ quotient
 print("The", root_of_unity_order, "th root of unity of extension field is: ", f_2_omega_n)
 
-######################################################################
-
+######################################################################
diff --git a/src/curves/g1_curve.rs b/src/curves/g1_curve.rs
@@ -0,0 +1,117 @@
+use std::ops::Add;
+
+use super::CurveParams;
+use crate::field::{gf_101::GF101, FiniteField};
+
+/// The Elliptic curve $y^2=x^3+3$, i.e.
+/// - a = 0
+/// - b = 3
+/// - generator todo
+/// - order todo
+/// - field element type todo, but mock with u64 - bad thor, u64 does not implement p3_field
+#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
+pub struct C101;
+
+impl CurveParams for C101 {
+  type FieldElement = GF101;
+
+  const EQUATION_A: Self::FieldElement = GF101::new(0);
+  const EQUATION_B: Self::FieldElement = GF101::new(3);
+  const GENERATOR: (Self::FieldElement, Self::FieldElement) = (GF101::new(1), Self::TWO);
+  const ORDER: u32 = GF101::ORDER;
+  const THREE: Self::FieldElement = GF101::new(3);
+  const TWO: Self::FieldElement = GF101::new(2);
+}
+
+mod test {
+  use super::*;
+  use crate::curves::AffinePoint;
+  type F = GF101;
+
+  #[test]
+  fn point_doubling() {
+    let g = AffinePoint::<C101>::generator();
+
+    let two_g = g.point_doubling();
+    let expected_2g = AffinePoint::<C101>::new(F::new(68), F::new(74));
+    let expected_negative_2g = AffinePoint::<C101>::new(F::new(68), F::new(27));
+    assert_eq!(two_g, expected_2g);
+    assert_eq!(-two_g, expected_negative_2g);
+
+    let four_g = two_g.point_doubling();
+    let expected_4g = AffinePoint::<C101>::new(F::new(65), F::new(98));
+    let expected_negative_4g = AffinePoint::<C101>::new(F::new(65), F::new(3));
+    assert_eq!(four_g, expected_4g);
+    assert_eq!(-four_g, expected_negative_4g);
+
+    let eight_g = four_g.point_doubling();
+    let expected_8g = AffinePoint::<C101>::new(F::new(18), F::new(49));
+    let expected_negative_8g = AffinePoint::<C101>::new(F::new(18), F::new(52));
+    assert_eq!(eight_g, expected_8g);
+    assert_eq!(-eight_g, expected_negative_8g);
+
+    let sixteen_g = eight_g.point_doubling();
+    let expected_16g = AffinePoint::<C101>::new(F::new(1), F::new(99));
+    let expected_negative_16g = AffinePoint::<C101>::new(F::new(1), F::new(2));
+    assert_eq!(sixteen_g, expected_16g);
+    assert_eq!(-sixteen_g, expected_negative_16g);
+    assert_eq!(g, -sixteen_g);
+  }
+
+  #[test]
+  fn order_17() {
+    let g = AffinePoint::<C101>::generator();
+    let mut g_double = g.point_doubling();
+    let mut count = 2;
+    while g_double != g && -g_double != g {
+      g_double = g_double.point_doubling();
+      count *= 2;
+    }
+    assert_eq!(count + 1, 17);
+  }
+
+  #[test]
+  fn point_addition() {
+    let g = AffinePoint::<C101>::generator();
+    let two_g = g.point_doubling();
+    let three_g = g + two_g;
+    let expected_3g = AffinePoint::<C101>::new(F::new(26), F::new(45));
+    let expected_negative_3g = AffinePoint::<C101>::new(F::new(26), F::new(56));
+    assert_eq!(three_g, expected_3g);
+    assert_eq!(-three_g, expected_negative_3g);
+
+    let four_g = g + three_g;
+    let expected_4g = AffinePoint::<C101>::new(F::new(65), F::new(98));
+    let expected_negative_4g = AffinePoint::<C101>::new(F::new(65), F::new(3));
+    assert_eq!(four_g, expected_4g);
+    assert_eq!(-four_g, expected_negative_4g);
+
+    let five_g = g + four_g;
+    let expected_5g = AffinePoint::<C101>::new(F::new(12), F::new(32));
+    let expected_negative_5g = AffinePoint::<C101>::new(F::new(12), F::new(69));
+    assert_eq!(five_g, expected_5g);
+    assert_eq!(-five_g, expected_negative_5g);
+
+    assert_eq!(g + AffinePoint::new_infty(), g);
+    assert_eq!(AffinePoint::new_infty() + g, g);
+    assert_eq!(g + (-g), AffinePoint::new_infty());
+  }
+
+  #[test]
+  fn scalar_multiplication_rhs() {
+    let g = AffinePoint::<C101>::generator();
+    let two_g = g * 2;
+    let expected_2g = g.point_doubling();
+    assert_eq!(two_g, expected_2g);
+    assert_eq!(-two_g, -expected_2g);
+  }
+
+  #[test]
+  fn scalar_multiplication_lhs() {
+    let g = AffinePoint::<C101>::generator();
+    let two_g = 2 * g;
+    let expected_2g = g.point_doubling();
+    assert_eq!(two_g, expected_2g);
+    assert_eq!(-two_g, -expected_2g);
+  }
+}
diff --git a/src/curves/g2_curve.rs b/src/curves/g2_curve.rs
@@ -0,0 +1,83 @@
+use std::ops::Add;
+
+use super::CurveParams;
+use crate::field::{gf_101::GF101, gf_101_2::QuadraticPlutoField, ExtensionField, FiniteField};
+
+#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
+pub struct G2Curve {}
+// The Elliptic curve $y^2=x^3+3$, i.e.
+// - a = 0
+// - b = 3
+
+impl CurveParams for G2Curve {
+  type FieldElement = QuadraticPlutoField<GF101>;
+
+  const EQUATION_A: Self::FieldElement = QuadraticPlutoField::<GF101>::ZERO;
+  const EQUATION_B: Self::FieldElement =
+    QuadraticPlutoField::<GF101>::new(GF101::new(3), GF101::ZERO);
+  const GENERATOR: (Self::FieldElement, Self::FieldElement) = (
+    QuadraticPlutoField::<GF101>::new(GF101::new(36), GF101::ZERO),
+    QuadraticPlutoField::<GF101>::new(GF101::ZERO, GF101::new(31)),
+  );
+  const ORDER: u32 = 289;
+  // extension field subgroup should have order r^2 where r is order of first group
+  const THREE: QuadraticPlutoField<GF101> =
+    QuadraticPlutoField::<GF101>::new(GF101::new(3), GF101::ZERO);
+  const TWO: QuadraticPlutoField<GF101> =
+    QuadraticPlutoField::<GF101>::new(GF101::TWO, GF101::ZERO);
+}
+
+// a naive impl with affine point
+
+impl G2Curve {
+  pub fn on_curve(
+    x: QuadraticPlutoField<GF101>,
+    y: QuadraticPlutoField<GF101>,
+  ) -> (QuadraticPlutoField<GF101>, QuadraticPlutoField<GF101>) {
+    println!("X: {:?}, Y: {:?}", x, y);
+    // TODO Continue working on this
+    //                  (   x  )  (  y   )  ( x , y )
+    // example: plug in ((36, 0), (0, 31)): (36, 31t)
+    // x = 36, y = 31t,
+    // curve : y^2=x^3+3,
+
+    // y = (31t)^2 = 52 * t^2
+    // check if there are any x terms, if not, element is in base field
+    let mut LHS = x;
+    let mut RHS = y;
+    if x.value[1] != GF101::ZERO {
+      LHS = x * x * (-GF101::new(2)) - Self::EQUATION_B;
+    } else {
+      LHS = x * x * x - Self::EQUATION_B;
+    }
+    if y.value[1] != GF101::ZERO {
+      // y has degree two so if there is a x -> there will be an x^2 term which we substitude with
+      // -2 since... TODO explain this and relationship to embedding degree
+      RHS *= -GF101::new(2);
+    }
+    // minus
+    LHS -= Self::EQUATION_B;
+    assert_eq!(LHS, RHS, "Point is not on curve");
+    (x, y)
+  }
+}
+
+mod test {
+  use super::*;
+  use crate::curves::AffinePoint;
+
+  // #[test]
+  // fn on_curve() {
+  //     let gen = G2Curve::on_curve(G2Curve::GENERATOR.0, G2Curve::GENERATOR.1);
+  // }
+
+  // #[test]
+  // fn doubling() {
+  //     let g = AffinePoint::<G2Curve>::generator();
+  //     println!("g: {:?}", g)
+
+  //     // want to asset that g  = (36, 31*X)
+  //     // right now this ^ fails to construct as it doesn't believe that the generator is a valid
+  // point on the curve     // want to asset that 2g = (90 , 82*X)
+  // }
+}