mirror of https://github.com/zcash/halo2.git
919 lines
31 KiB
Rust
919 lines
31 KiB
Rust
//! Elliptic curve operations.
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use std::fmt::Debug;
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use halo2_proofs::{
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arithmetic::CurveAffine,
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circuit::{Chip, Layouter, Value},
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plonk::Error,
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};
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use crate::utilities::UtilitiesInstructions;
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pub mod chip;
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/// The set of circuit instructions required to use the ECC gadgets.
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pub trait EccInstructions<C: CurveAffine>:
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Chip<C::Base> + UtilitiesInstructions<C::Base> + Clone + Debug + Eq
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{
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/// Variable representing a scalar used in variable-base scalar mul.
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///
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/// This type is treated as a full-width scalar. However, if `Self` implements
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/// [`BaseFitsInScalarInstructions`] then this may also be constructed from an element
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/// of the base field.
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type ScalarVar: Clone + Debug;
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/// Variable representing a full-width element of the elliptic curve's
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/// scalar field, to be used for fixed-base scalar mul.
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type ScalarFixed: Clone + Debug;
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/// Variable representing a signed short element of the elliptic curve's
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/// scalar field, to be used for fixed-base scalar mul.
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///
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/// A `ScalarFixedShort` must be in the range [-(2^64 - 1), 2^64 - 1].
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type ScalarFixedShort: Clone + Debug;
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/// Variable representing an elliptic curve point.
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type Point: From<Self::NonIdentityPoint> + Clone + Debug;
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/// Variable representing a non-identity elliptic curve point.
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type NonIdentityPoint: Clone + Debug;
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/// Variable representing the affine short Weierstrass x-coordinate of an
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/// elliptic curve point.
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type X: Clone + Debug;
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/// Enumeration of the set of fixed bases to be used in scalar mul.
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/// TODO: When associated consts can be used as const generics, introduce
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/// `Self::NUM_WINDOWS`, `Self::NUM_WINDOWS_BASE_FIELD`, `Self::NUM_WINDOWS_SHORT`
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/// and use them to differentiate `FixedPoints` types.
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type FixedPoints: FixedPoints<C>;
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/// Constrains point `a` to be equal in value to point `b`.
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fn constrain_equal(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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a: &Self::Point,
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b: &Self::Point,
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) -> Result<(), Error>;
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/// Witnesses the given point as a private input to the circuit.
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/// This allows the point to be the identity, mapped to (0, 0) in
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/// affine coordinates.
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fn witness_point(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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value: Value<C>,
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) -> Result<Self::Point, Error>;
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/// Witnesses the given point as a private input to the circuit.
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/// This returns an error if the point is the identity.
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fn witness_point_non_id(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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value: Value<C>,
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) -> Result<Self::NonIdentityPoint, Error>;
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/// Witnesses a full-width scalar to be used in variable-base multiplication.
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fn witness_scalar_var(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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value: Value<C::Scalar>,
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) -> Result<Self::ScalarVar, Error>;
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/// Witnesses a full-width scalar to be used in fixed-base multiplication.
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fn witness_scalar_fixed(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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value: Value<C::Scalar>,
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) -> Result<Self::ScalarFixed, Error>;
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/// Converts a magnitude and sign that exists as variables in the circuit into a
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/// signed short scalar to be used in fixed-base scalar multiplication.
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fn scalar_fixed_from_signed_short(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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magnitude_sign: (Self::Var, Self::Var),
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) -> Result<Self::ScalarFixedShort, Error>;
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/// Extracts the x-coordinate of a point.
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fn extract_p<Point: Into<Self::Point> + Clone>(point: &Point) -> Self::X;
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/// Performs incomplete point addition, returning `a + b`.
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///
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/// This returns an error in exceptional cases.
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fn add_incomplete(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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a: &Self::NonIdentityPoint,
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b: &Self::NonIdentityPoint,
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) -> Result<Self::NonIdentityPoint, Error>;
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/// Performs complete point addition, returning `a + b`.
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fn add<A: Into<Self::Point> + Clone, B: Into<Self::Point> + Clone>(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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a: &A,
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b: &B,
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) -> Result<Self::Point, Error>;
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/// Performs variable-base scalar multiplication, returning `[scalar] base`.
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fn mul(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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scalar: &Self::ScalarVar,
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base: &Self::NonIdentityPoint,
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) -> Result<(Self::Point, Self::ScalarVar), Error>;
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/// Performs fixed-base scalar multiplication using a full-width scalar, returning `[scalar] base`.
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fn mul_fixed(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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scalar: &Self::ScalarFixed,
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base: &<Self::FixedPoints as FixedPoints<C>>::FullScalar,
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) -> Result<(Self::Point, Self::ScalarFixed), Error>;
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/// Performs fixed-base scalar multiplication using a short signed scalar, returning
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/// `[scalar] base`.
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fn mul_fixed_short(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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scalar: &Self::ScalarFixedShort,
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base: &<Self::FixedPoints as FixedPoints<C>>::ShortScalar,
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) -> Result<(Self::Point, Self::ScalarFixedShort), Error>;
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/// Performs fixed-base scalar multiplication using a base field element as the scalar.
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/// In the current implementation, this base field element must be output from another
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/// instruction.
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fn mul_fixed_base_field_elem(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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base_field_elem: Self::Var,
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base: &<Self::FixedPoints as FixedPoints<C>>::Base,
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) -> Result<Self::Point, Error>;
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}
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/// Instructions that can be implemented for a curve whose base field fits into
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/// its scalar field.
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pub trait BaseFitsInScalarInstructions<C: CurveAffine>: EccInstructions<C> {
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/// Converts a base field element that exists as a variable in the circuit
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/// into a scalar to be used in variable-base scalar multiplication.
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fn scalar_var_from_base(
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&self,
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layouter: &mut impl Layouter<C::Base>,
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base: &Self::Var,
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) -> Result<Self::ScalarVar, Error>;
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}
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/// Defines the fixed points for a given instantiation of the ECC chip.
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pub trait FixedPoints<C: CurveAffine>: Debug + Eq + Clone {
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/// Fixed points that can be used with full-width scalar multiplication.
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type FullScalar: Debug + Eq + Clone;
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/// Fixed points that can be used with short scalar multiplication.
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type ShortScalar: Debug + Eq + Clone;
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/// Fixed points that can be multiplied by base field elements.
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type Base: Debug + Eq + Clone;
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}
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/// An integer representing an element of the scalar field for a specific elliptic curve.
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#[derive(Debug)]
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pub struct ScalarVar<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: EccChip::ScalarVar,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C>> ScalarVar<C, EccChip> {
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/// Witnesses the given full-width scalar.
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///
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/// Depending on the `EccChip` implementation, this may either witness the scalar
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/// immediately, or delay witnessing until its first use in [`NonIdentityPoint::mul`].
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pub fn new(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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value: Value<C::Scalar>,
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) -> Result<Self, Error> {
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let scalar = chip.witness_scalar_var(&mut layouter, value);
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scalar.map(|inner| ScalarVar { chip, inner })
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}
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}
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impl<C: CurveAffine, EccChip: BaseFitsInScalarInstructions<C>> ScalarVar<C, EccChip> {
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/// Constructs a scalar from an existing base-field element.
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pub fn from_base(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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base: &EccChip::Var,
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) -> Result<Self, Error> {
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let scalar = chip.scalar_var_from_base(&mut layouter, base);
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scalar.map(|inner| ScalarVar { chip, inner })
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}
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}
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/// An integer representing an element of the scalar field for a specific elliptic curve,
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/// for [`FixedPoint`] scalar multiplication.
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#[derive(Debug)]
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pub struct ScalarFixed<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: EccChip::ScalarFixed,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C>> ScalarFixed<C, EccChip> {
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/// Witnesses the given full-width scalar.
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///
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/// Depending on the `EccChip` implementation, this may either witness the scalar
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/// immediately, or delay witnessing until its first use in [`FixedPoint::mul`].
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pub fn new(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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value: Value<C::Scalar>,
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) -> Result<Self, Error> {
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let scalar = chip.witness_scalar_fixed(&mut layouter, value);
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scalar.map(|inner| ScalarFixed { chip, inner })
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}
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}
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/// A signed short (64-bit) integer represented as an element of the scalar field for a
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/// specific elliptic curve, to be used for [`FixedPointShort`] scalar multiplication.
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#[derive(Debug)]
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pub struct ScalarFixedShort<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: EccChip::ScalarFixedShort,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C>> ScalarFixedShort<C, EccChip> {
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/// Converts the given signed short scalar.
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///
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/// `magnitude_sign` must be a tuple of two circuit-assigned values:
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/// - An unsigned integer of at most 64 bits.
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/// - A sign value that is either 1 or -1.
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///
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/// Depending on the `EccChip` implementation, the scalar may either be constrained
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/// immediately by this constructor, or lazily constrained when it is first used in
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/// [`FixedPointShort::mul`].
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pub fn new(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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magnitude_sign: (EccChip::Var, EccChip::Var),
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) -> Result<Self, Error> {
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let scalar = chip.scalar_fixed_from_signed_short(&mut layouter, magnitude_sign);
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scalar.map(|inner| ScalarFixedShort { chip, inner })
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}
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}
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/// A point on a specific elliptic curve that is guaranteed to not be the identity.
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#[derive(Copy, Clone, Debug)]
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pub struct NonIdentityPoint<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: EccChip::NonIdentityPoint,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C>> NonIdentityPoint<C, EccChip> {
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/// Constructs a new point with the given value.
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pub fn new(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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value: Value<C>,
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) -> Result<Self, Error> {
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let point = chip.witness_point_non_id(&mut layouter, value);
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point.map(|inner| NonIdentityPoint { chip, inner })
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}
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/// Constrains this point to be equal in value to another point.
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pub fn constrain_equal<Other: Into<Point<C, EccChip>> + Clone>(
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&self,
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mut layouter: impl Layouter<C::Base>,
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other: &Other,
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) -> Result<(), Error> {
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let other: Point<C, EccChip> = (other.clone()).into();
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self.chip.constrain_equal(
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&mut layouter,
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&Point::<C, EccChip>::from(self.clone()).inner,
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&other.inner,
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)
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}
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/// Returns the inner point.
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pub fn inner(&self) -> &EccChip::NonIdentityPoint {
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&self.inner
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}
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/// Extracts the x-coordinate of a point.
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pub fn extract_p(&self) -> X<C, EccChip> {
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X::from_inner(self.chip.clone(), EccChip::extract_p(&self.inner))
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}
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/// Wraps the given point (obtained directly from an instruction) in a gadget.
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pub fn from_inner(chip: EccChip, inner: EccChip::NonIdentityPoint) -> Self {
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NonIdentityPoint { chip, inner }
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}
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/// Returns `self + other` using complete addition.
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pub fn add<Other: Into<Point<C, EccChip>> + Clone>(
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&self,
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mut layouter: impl Layouter<C::Base>,
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other: &Other,
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) -> Result<Point<C, EccChip>, Error> {
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let other: Point<C, EccChip> = (other.clone()).into();
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assert_eq!(self.chip, other.chip);
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self.chip
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.add(&mut layouter, &self.inner, &other.inner)
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.map(|inner| Point {
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chip: self.chip.clone(),
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inner,
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})
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}
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/// Returns `self + other` using incomplete addition.
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/// The arguments are type-constrained not to be the identity point,
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/// and since exceptional cases return an Error, the result also cannot
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/// be the identity point.
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pub fn add_incomplete(
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&self,
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mut layouter: impl Layouter<C::Base>,
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other: &Self,
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) -> Result<Self, Error> {
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assert_eq!(self.chip, other.chip);
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self.chip
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.add_incomplete(&mut layouter, &self.inner, &other.inner)
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.map(|inner| NonIdentityPoint {
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chip: self.chip.clone(),
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inner,
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})
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}
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/// Returns `[by] self`.
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#[allow(clippy::type_complexity)]
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pub fn mul(
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&self,
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mut layouter: impl Layouter<C::Base>,
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by: ScalarVar<C, EccChip>,
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) -> Result<(Point<C, EccChip>, ScalarVar<C, EccChip>), Error> {
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assert_eq!(self.chip, by.chip);
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self.chip
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.mul(&mut layouter, &by.inner, &self.inner.clone())
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.map(|(point, scalar)| {
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(
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Point {
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chip: self.chip.clone(),
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inner: point,
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},
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ScalarVar {
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chip: self.chip.clone(),
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inner: scalar,
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},
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)
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})
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}
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq>
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From<NonIdentityPoint<C, EccChip>> for Point<C, EccChip>
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{
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fn from(non_id_point: NonIdentityPoint<C, EccChip>) -> Self {
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Self {
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chip: non_id_point.chip,
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inner: non_id_point.inner.into(),
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}
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}
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}
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/// A point on a specific elliptic curve.
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#[derive(Copy, Clone, Debug)]
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pub struct Point<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq> {
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chip: EccChip,
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inner: EccChip::Point,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq> Point<C, EccChip> {
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/// Constructs a new point with the given value.
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pub fn new(
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chip: EccChip,
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mut layouter: impl Layouter<C::Base>,
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value: Value<C>,
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) -> Result<Self, Error> {
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let point = chip.witness_point(&mut layouter, value);
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point.map(|inner| Point { chip, inner })
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}
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/// Constrains this point to be equal in value to another point.
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pub fn constrain_equal<Other: Into<Point<C, EccChip>> + Clone>(
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&self,
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mut layouter: impl Layouter<C::Base>,
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other: &Other,
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) -> Result<(), Error> {
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let other: Point<C, EccChip> = (other.clone()).into();
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self.chip
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.constrain_equal(&mut layouter, &self.inner, &other.inner)
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}
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/// Returns the inner point.
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pub fn inner(&self) -> &EccChip::Point {
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&self.inner
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}
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/// Extracts the x-coordinate of a point.
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pub fn extract_p(&self) -> X<C, EccChip> {
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X::from_inner(self.chip.clone(), EccChip::extract_p(&self.inner))
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}
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/// Wraps the given point (obtained directly from an instruction) in a gadget.
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pub fn from_inner(chip: EccChip, inner: EccChip::Point) -> Self {
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Point { chip, inner }
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}
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/// Returns `self + other` using complete addition.
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pub fn add<Other: Into<Point<C, EccChip>> + Clone>(
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&self,
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mut layouter: impl Layouter<C::Base>,
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other: &Other,
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) -> Result<Point<C, EccChip>, Error> {
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let other: Point<C, EccChip> = (other.clone()).into();
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assert_eq!(self.chip, other.chip);
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self.chip
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.add(&mut layouter, &self.inner, &other.inner)
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.map(|inner| Point {
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chip: self.chip.clone(),
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inner,
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})
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}
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}
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/// The affine short Weierstrass x-coordinate of a point on a specific elliptic curve.
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#[derive(Debug)]
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pub struct X<C: CurveAffine, EccChip: EccInstructions<C>> {
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inner: EccChip::X,
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}
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impl<C: CurveAffine, EccChip: EccInstructions<C>> X<C, EccChip> {
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/// Wraps the given x-coordinate (obtained directly from an instruction) in a gadget.
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pub fn from_inner(chip: EccChip, inner: EccChip::X) -> Self {
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let _ = chip; // unused
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X { inner }
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}
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/// Returns the inner x-coordinate.
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pub fn inner(&self) -> &EccChip::X {
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&self.inner
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}
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}
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/// Precomputed multiples of a fixed point, for full-width scalar multiplication.
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///
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/// Fixing the curve point enables window tables to be baked into the circuit, making
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/// scalar multiplication more efficient. These window tables are tuned to full-width
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/// scalar multiplication.
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#[derive(Clone, Debug)]
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pub struct FixedPoint<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: <EccChip::FixedPoints as FixedPoints<C>>::FullScalar,
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}
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/// Precomputed multiples of a fixed point, that can be multiplied by base-field elements.
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///
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/// Fixing the curve point enables window tables to be baked into the circuit, making
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/// scalar multiplication more efficient. These window tables are tuned to scalar
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/// multiplication by base-field elements.
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#[derive(Clone, Debug)]
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pub struct FixedPointBaseField<C: CurveAffine, EccChip: EccInstructions<C>> {
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chip: EccChip,
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inner: <EccChip::FixedPoints as FixedPoints<C>>::Base,
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}
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/// Precomputed multiples of a fixed point, for short signed scalar multiplication.
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#[derive(Clone, Debug)]
|
|
pub struct FixedPointShort<C: CurveAffine, EccChip: EccInstructions<C>> {
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|
chip: EccChip,
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|
inner: <EccChip::FixedPoints as FixedPoints<C>>::ShortScalar,
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|
}
|
|
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|
impl<C: CurveAffine, EccChip: EccInstructions<C>> FixedPoint<C, EccChip> {
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|
#[allow(clippy::type_complexity)]
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/// Returns `[by] self`.
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pub fn mul(
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|
&self,
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mut layouter: impl Layouter<C::Base>,
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|
by: ScalarFixed<C, EccChip>,
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|
) -> Result<(Point<C, EccChip>, ScalarFixed<C, EccChip>), Error> {
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|
assert_eq!(self.chip, by.chip);
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|
self.chip
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.mul_fixed(&mut layouter, &by.inner, &self.inner)
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.map(|(point, scalar)| {
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(
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|
Point {
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chip: self.chip.clone(),
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inner: point,
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},
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ScalarFixed {
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chip: self.chip.clone(),
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inner: scalar,
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},
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)
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})
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}
|
|
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/// Wraps the given fixed base (obtained directly from an instruction) in a gadget.
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|
pub fn from_inner(
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chip: EccChip,
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inner: <EccChip::FixedPoints as FixedPoints<C>>::FullScalar,
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|
) -> Self {
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Self { chip, inner }
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|
}
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|
}
|
|
|
|
impl<C: CurveAffine, EccChip: EccInstructions<C>> FixedPointBaseField<C, EccChip> {
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|
#[allow(clippy::type_complexity)]
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|
/// Returns `[by] self`.
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pub fn mul(
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|
&self,
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|
mut layouter: impl Layouter<C::Base>,
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|
by: EccChip::Var,
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|
) -> Result<Point<C, EccChip>, Error> {
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|
self.chip
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|
.mul_fixed_base_field_elem(&mut layouter, by, &self.inner)
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|
.map(|inner| Point {
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|
chip: self.chip.clone(),
|
|
inner,
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|
})
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|
}
|
|
|
|
/// Wraps the given fixed base (obtained directly from an instruction) in a gadget.
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|
pub fn from_inner(
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|
chip: EccChip,
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inner: <EccChip::FixedPoints as FixedPoints<C>>::Base,
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|
) -> Self {
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Self { chip, inner }
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|
}
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|
}
|
|
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impl<C: CurveAffine, EccChip: EccInstructions<C>> FixedPointShort<C, EccChip> {
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|
#[allow(clippy::type_complexity)]
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|
/// Returns `[by] self`.
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|
pub fn mul(
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|
&self,
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|
mut layouter: impl Layouter<C::Base>,
|
|
by: ScalarFixedShort<C, EccChip>,
|
|
) -> Result<(Point<C, EccChip>, ScalarFixedShort<C, EccChip>), Error> {
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assert_eq!(self.chip, by.chip);
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|
self.chip
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.mul_fixed_short(&mut layouter, &by.inner, &self.inner)
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.map(|(point, scalar)| {
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(
|
|
Point {
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chip: self.chip.clone(),
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|
inner: point,
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},
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ScalarFixedShort {
|
|
chip: self.chip.clone(),
|
|
inner: scalar,
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|
},
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|
)
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|
})
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|
}
|
|
|
|
/// Wraps the given fixed base (obtained directly from an instruction) in a gadget.
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|
pub fn from_inner(
|
|
chip: EccChip,
|
|
inner: <EccChip::FixedPoints as FixedPoints<C>>::ShortScalar,
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|
) -> Self {
|
|
Self { chip, inner }
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|
}
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|
}
|
|
|
|
#[cfg(test)]
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|
pub(crate) mod tests {
|
|
use ff::PrimeField;
|
|
use group::{prime::PrimeCurveAffine, Curve, Group};
|
|
|
|
use halo2_proofs::{
|
|
circuit::{Layouter, SimpleFloorPlanner, Value},
|
|
dev::MockProver,
|
|
plonk::{Circuit, ConstraintSystem, Error},
|
|
};
|
|
use lazy_static::lazy_static;
|
|
use pasta_curves::pallas;
|
|
|
|
use super::{
|
|
chip::{
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|
find_zs_and_us, BaseFieldElem, EccChip, EccConfig, FixedPoint, FullScalar, ShortScalar,
|
|
H, NUM_WINDOWS, NUM_WINDOWS_SHORT,
|
|
},
|
|
FixedPoints,
|
|
};
|
|
use crate::utilities::lookup_range_check::LookupRangeCheckConfig;
|
|
|
|
#[derive(Debug, Eq, PartialEq, Clone)]
|
|
pub(crate) struct TestFixedBases;
|
|
#[derive(Debug, Eq, PartialEq, Clone)]
|
|
pub(crate) struct FullWidth(pallas::Affine, &'static [(u64, [pallas::Base; H])]);
|
|
#[derive(Debug, Eq, PartialEq, Clone)]
|
|
pub(crate) struct BaseField;
|
|
#[derive(Debug, Eq, PartialEq, Clone)]
|
|
pub(crate) struct Short;
|
|
|
|
lazy_static! {
|
|
static ref BASE: pallas::Affine = pallas::Point::generator().to_affine();
|
|
static ref ZS_AND_US: Vec<(u64, [pallas::Base; H])> =
|
|
find_zs_and_us(*BASE, NUM_WINDOWS).unwrap();
|
|
static ref ZS_AND_US_SHORT: Vec<(u64, [pallas::Base; H])> =
|
|
find_zs_and_us(*BASE, NUM_WINDOWS_SHORT).unwrap();
|
|
}
|
|
|
|
impl FullWidth {
|
|
pub(crate) fn from_pallas_generator() -> Self {
|
|
FullWidth(*BASE, &ZS_AND_US)
|
|
}
|
|
|
|
pub(crate) fn from_parts(
|
|
base: pallas::Affine,
|
|
zs_and_us: &'static [(u64, [pallas::Base; H])],
|
|
) -> Self {
|
|
FullWidth(base, zs_and_us)
|
|
}
|
|
}
|
|
|
|
impl FixedPoint<pallas::Affine> for FullWidth {
|
|
type FixedScalarKind = FullScalar;
|
|
|
|
fn generator(&self) -> pallas::Affine {
|
|
self.0
|
|
}
|
|
|
|
fn u(&self) -> Vec<[[u8; 32]; H]> {
|
|
self.1
|
|
.iter()
|
|
.map(|(_, us)| {
|
|
[
|
|
us[0].to_repr(),
|
|
us[1].to_repr(),
|
|
us[2].to_repr(),
|
|
us[3].to_repr(),
|
|
us[4].to_repr(),
|
|
us[5].to_repr(),
|
|
us[6].to_repr(),
|
|
us[7].to_repr(),
|
|
]
|
|
})
|
|
.collect()
|
|
}
|
|
|
|
fn z(&self) -> Vec<u64> {
|
|
self.1.iter().map(|(z, _)| *z).collect()
|
|
}
|
|
}
|
|
|
|
impl FixedPoint<pallas::Affine> for BaseField {
|
|
type FixedScalarKind = BaseFieldElem;
|
|
|
|
fn generator(&self) -> pallas::Affine {
|
|
*BASE
|
|
}
|
|
|
|
fn u(&self) -> Vec<[[u8; 32]; H]> {
|
|
ZS_AND_US
|
|
.iter()
|
|
.map(|(_, us)| {
|
|
[
|
|
us[0].to_repr(),
|
|
us[1].to_repr(),
|
|
us[2].to_repr(),
|
|
us[3].to_repr(),
|
|
us[4].to_repr(),
|
|
us[5].to_repr(),
|
|
us[6].to_repr(),
|
|
us[7].to_repr(),
|
|
]
|
|
})
|
|
.collect()
|
|
}
|
|
|
|
fn z(&self) -> Vec<u64> {
|
|
ZS_AND_US.iter().map(|(z, _)| *z).collect()
|
|
}
|
|
}
|
|
|
|
impl FixedPoint<pallas::Affine> for Short {
|
|
type FixedScalarKind = ShortScalar;
|
|
|
|
fn generator(&self) -> pallas::Affine {
|
|
*BASE
|
|
}
|
|
|
|
fn u(&self) -> Vec<[[u8; 32]; H]> {
|
|
ZS_AND_US_SHORT
|
|
.iter()
|
|
.map(|(_, us)| {
|
|
[
|
|
us[0].to_repr(),
|
|
us[1].to_repr(),
|
|
us[2].to_repr(),
|
|
us[3].to_repr(),
|
|
us[4].to_repr(),
|
|
us[5].to_repr(),
|
|
us[6].to_repr(),
|
|
us[7].to_repr(),
|
|
]
|
|
})
|
|
.collect()
|
|
}
|
|
|
|
fn z(&self) -> Vec<u64> {
|
|
ZS_AND_US_SHORT.iter().map(|(z, _)| *z).collect()
|
|
}
|
|
}
|
|
|
|
impl FixedPoints<pallas::Affine> for TestFixedBases {
|
|
type FullScalar = FullWidth;
|
|
type ShortScalar = Short;
|
|
type Base = BaseField;
|
|
}
|
|
|
|
struct MyCircuit {
|
|
test_errors: bool,
|
|
}
|
|
|
|
#[allow(non_snake_case)]
|
|
impl Circuit<pallas::Base> for MyCircuit {
|
|
type Config = EccConfig<TestFixedBases>;
|
|
type FloorPlanner = SimpleFloorPlanner;
|
|
|
|
fn without_witnesses(&self) -> Self {
|
|
MyCircuit { test_errors: false }
|
|
}
|
|
|
|
fn configure(meta: &mut ConstraintSystem<pallas::Base>) -> Self::Config {
|
|
let advices = [
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
meta.advice_column(),
|
|
];
|
|
let lookup_table = meta.lookup_table_column();
|
|
let lagrange_coeffs = [
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
meta.fixed_column(),
|
|
];
|
|
// Shared fixed column for loading constants
|
|
let constants = meta.fixed_column();
|
|
meta.enable_constant(constants);
|
|
|
|
let range_check = LookupRangeCheckConfig::configure(meta, advices[9], lookup_table);
|
|
EccChip::<TestFixedBases>::configure(meta, advices, lagrange_coeffs, range_check)
|
|
}
|
|
|
|
fn synthesize(
|
|
&self,
|
|
config: Self::Config,
|
|
mut layouter: impl Layouter<pallas::Base>,
|
|
) -> Result<(), Error> {
|
|
let chip = EccChip::construct(config.clone());
|
|
|
|
// Load 10-bit lookup table. In the Action circuit, this will be
|
|
// provided by the Sinsemilla chip.
|
|
config.lookup_config.load(&mut layouter)?;
|
|
|
|
// Generate a random non-identity point P
|
|
let p_val = pallas::Point::random(rand::rngs::OsRng).to_affine(); // P
|
|
let p = super::NonIdentityPoint::new(
|
|
chip.clone(),
|
|
layouter.namespace(|| "P"),
|
|
Value::known(p_val),
|
|
)?;
|
|
let p_neg = -p_val;
|
|
let p_neg = super::NonIdentityPoint::new(
|
|
chip.clone(),
|
|
layouter.namespace(|| "-P"),
|
|
Value::known(p_neg),
|
|
)?;
|
|
|
|
// Generate a random non-identity point Q
|
|
let q_val = pallas::Point::random(rand::rngs::OsRng).to_affine(); // Q
|
|
let q = super::NonIdentityPoint::new(
|
|
chip.clone(),
|
|
layouter.namespace(|| "Q"),
|
|
Value::known(q_val),
|
|
)?;
|
|
|
|
// Make sure P and Q are not the same point.
|
|
assert_ne!(p_val, q_val);
|
|
|
|
// Test that we can witness the identity as a point, but not as a non-identity point.
|
|
{
|
|
let _ = super::Point::new(
|
|
chip.clone(),
|
|
layouter.namespace(|| "identity"),
|
|
Value::known(pallas::Affine::identity()),
|
|
)?;
|
|
|
|
super::NonIdentityPoint::new(
|
|
chip.clone(),
|
|
layouter.namespace(|| "identity"),
|
|
Value::known(pallas::Affine::identity()),
|
|
)
|
|
.expect_err("Trying to witness the identity should return an error");
|
|
}
|
|
|
|
// Test witness non-identity point
|
|
{
|
|
super::chip::witness_point::tests::test_witness_non_id(
|
|
chip.clone(),
|
|
layouter.namespace(|| "witness non-identity point"),
|
|
)
|
|
}
|
|
|
|
// Test complete addition
|
|
{
|
|
super::chip::add::tests::test_add(
|
|
chip.clone(),
|
|
layouter.namespace(|| "complete addition"),
|
|
p_val,
|
|
&p,
|
|
q_val,
|
|
&q,
|
|
&p_neg,
|
|
)?;
|
|
}
|
|
|
|
// Test incomplete addition
|
|
{
|
|
super::chip::add_incomplete::tests::test_add_incomplete(
|
|
chip.clone(),
|
|
layouter.namespace(|| "incomplete addition"),
|
|
p_val,
|
|
&p,
|
|
q_val,
|
|
&q,
|
|
&p_neg,
|
|
self.test_errors,
|
|
)?;
|
|
}
|
|
|
|
// Test variable-base scalar multiplication
|
|
{
|
|
super::chip::mul::tests::test_mul(
|
|
chip.clone(),
|
|
layouter.namespace(|| "variable-base scalar mul"),
|
|
&p,
|
|
p_val,
|
|
)?;
|
|
}
|
|
|
|
// Test full-width fixed-base scalar multiplication
|
|
{
|
|
super::chip::mul_fixed::full_width::tests::test_mul_fixed(
|
|
chip.clone(),
|
|
layouter.namespace(|| "full-width fixed-base scalar mul"),
|
|
)?;
|
|
}
|
|
|
|
// Test signed short fixed-base scalar multiplication
|
|
{
|
|
super::chip::mul_fixed::short::tests::test_mul_fixed_short(
|
|
chip.clone(),
|
|
layouter.namespace(|| "signed short fixed-base scalar mul"),
|
|
)?;
|
|
}
|
|
|
|
// Test fixed-base scalar multiplication with a base field element
|
|
{
|
|
super::chip::mul_fixed::base_field_elem::tests::test_mul_fixed_base_field(
|
|
chip,
|
|
layouter.namespace(|| "fixed-base scalar mul with base field element"),
|
|
)?;
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn ecc_chip() {
|
|
let k = 13;
|
|
let circuit = MyCircuit { test_errors: true };
|
|
let prover = MockProver::run(k, &circuit, vec![]).unwrap();
|
|
assert_eq!(prover.verify(), Ok(()))
|
|
}
|
|
|
|
#[cfg(feature = "test-dev-graph")]
|
|
#[test]
|
|
fn print_ecc_chip() {
|
|
use plotters::prelude::*;
|
|
|
|
let root = BitMapBackend::new("ecc-chip-layout.png", (1024, 7680)).into_drawing_area();
|
|
root.fill(&WHITE).unwrap();
|
|
let root = root.titled("Ecc Chip Layout", ("sans-serif", 60)).unwrap();
|
|
|
|
let circuit = MyCircuit { test_errors: false };
|
|
halo2_proofs::dev::CircuitLayout::default()
|
|
.render(13, &circuit, &root)
|
|
.unwrap();
|
|
}
|
|
}
|