Class BLS12_381G1CurveProcessor

java.lang.Object
org.bouncycastle.crypto.hash2curve.impl.BLS12_381G1CurveProcessor
All Implemented Interfaces:
CurveProcessor
public class BLS12_381G1CurveProcessor extends Object implements CurveProcessor
CurveProcessor for the BLS12381G1_XMD:SHA-256_SSWU_RO_ hash-to-curve suite. Cofactor clearing is done by scalar-multiplication by BLS12_381G1.H_EFF (Bowe's fast cofactor clear), as mandated by RFC 9380 sec. 8.8.1.

  • Constructor Details

    • BLS12_381G1CurveProcessor

      public BLS12_381G1CurveProcessor()

  • Method Details

    • add

      public ECPoint add(ECPoint p, ECPoint q)
      Description copied from interface: CurveProcessor
      Add two points in the curve group. Semantics are curve-model specific.
      Specified by:
      add in interface CurveProcessor

    • clearCofactor

      public ECPoint clearCofactor(ECPoint ecPoint)
      Description copied from interface: CurveProcessor
      Clears the cofactor from the given elliptic curve point.
      Specified by:
      clearCofactor in interface CurveProcessor
      Parameters:
      ecPoint - the elliptic curve point to process
      Returns:
      the elliptic curve point with the cofactor cleared

    • mapToAffineXY

      public AffineXY mapToAffineXY(ECPoint p)
      Description copied from interface: CurveProcessor
      Converts an elliptic-curve point into the affine (x, y) coordinate representation defined by the hash-to-curve suite.

      The returned coordinates are intended for serialization, testing, and interoperability with the reference outputs defined in RFC 9380. For most Weierstrass curves, this is simply the affine (x, y) coordinates of the given point. For curves that use a different coordinate model in the specification (e.g. Montgomery curves such as curve25519), this method applies the appropriate coordinate transformation.

      This method does not change the underlying group element represented by the point. It only changes how that point is expressed as field elements. The input point is expected to be a valid point on the curve used by the implementation.

      Specified by:
      mapToAffineXY in interface CurveProcessor
      Parameters:
      p - a valid elliptic-curve point
      Returns:
      the affine (x, y) coordinates corresponding to the suite-specific representation of the given point