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Add FixedPointShort associated type

This commit is contained in:
therealyingtong 2021-05-06 15:42:01 +08:00
parent 6a64bc1c37
commit db60fd2262
1 changed files with 13 additions and 3 deletions
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16
src/circuit/gadget/ecc.rs
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@ -34,6 +34,9 @@ pub trait EccInstructions<C: CurveAffine>: Chip<C::Base> {
type FixedPoints: Clone + Debug; type FixedPoints: Clone + Debug;
/// Variable representing a fixed elliptic curve point (constant in the circuit). /// Variable representing a fixed elliptic curve point (constant in the circuit).
type FixedPoint: Clone + Debug; type FixedPoint: Clone + Debug;
/// Variable representing a fixed elliptic curve point (constant in the circuit)
/// to be used in scalar multiplication with a short signed exponent.
type FixedPointShort: Clone + Debug;
/// Witnesses the given base field element as a private input to the circuit for variable-base scalar mul. /// Witnesses the given base field element as a private input to the circuit for variable-base scalar mul.
fn witness_scalar_var( fn witness_scalar_var(
@ -71,6 +74,13 @@ pub trait EccInstructions<C: CurveAffine>: Chip<C::Base> {
/// parts of the circuit where the fixed base is used. /// parts of the circuit where the fixed base is used.
fn get_fixed(&self, fixed_points: Self::FixedPoints) -> Result<Self::FixedPoint, Error>; fn get_fixed(&self, fixed_points: Self::FixedPoints) -> Result<Self::FixedPoint, Error>;
/// Returns a fixed point to be used in scalar multiplication with a signed
/// short exponent.
fn get_fixed_short(
&self,
fixed_points: Self::FixedPoints,
) -> Result<Self::FixedPointShort, Error>;
/// Performs incomplete point addition, returning `a + b`. /// Performs incomplete point addition, returning `a + b`.
fn add_incomplete( fn add_incomplete(
&self, &self,
@ -108,7 +118,7 @@ pub trait EccInstructions<C: CurveAffine>: Chip<C::Base> {
&self, &self,
layouter: &mut impl Layouter<C::Base>, layouter: &mut impl Layouter<C::Base>,
scalar: &Self::ScalarFixedShort, scalar: &Self::ScalarFixedShort,
base: &Self::FixedPoint, base: &Self::FixedPointShort,
) -> Result<Self::Point, Error>; ) -> Result<Self::Point, Error>;
} }
@ -299,13 +309,13 @@ impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug> FixedPoint<C,
#[derive(Clone, Debug)] #[derive(Clone, Debug)]
pub struct FixedPointShort<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug> { pub struct FixedPointShort<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug> {
chip: EccChip, chip: EccChip,
inner: EccChip::FixedPoint, inner: EccChip::FixedPointShort,
} }
impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug> FixedPointShort<C, EccChip> { impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug> FixedPointShort<C, EccChip> {
/// Gets a reference to the specified fixed point in the circuit. /// Gets a reference to the specified fixed point in the circuit.
pub fn get(chip: EccChip, point: EccChip::FixedPoints) -> Result<Self, Error> { pub fn get(chip: EccChip, point: EccChip::FixedPoints) -> Result<Self, Error> {
chip.get_fixed(point) chip.get_fixed_short(point)
.map(|inner| FixedPointShort { chip, inner }) .map(|inner| FixedPointShort { chip, inner })
} }