Package org.bouncycastle.math.ec.sm9

Class SM9Pairing

  • public class SM9Pairing
extends java.lang.Object
    The SM9 R-ate pairing e: G1 x G2 -> G_T over the 256-bit BN curve (GM/T 0044.5-2016). Computed as the optimal-ate/R-ate Miller loop with loop parameter 6t+2, a two-term Frobenius tail, and the final exponentiation f^((q^12-1)/N).

    This is a correctness-first reference implementation: the Miller loop runs in F_p12 on the twist image, and the Frobenius/final exponentiation are ordinary F_p12 exponentiations. It is deliberately straightforward, not optimised.

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static Fp12 pairing​(ECPoint p, SM9G2Point q)
      e(P, Q) for P in G1 (a point of E(F_q)) and Q in G2 (a point of the twist).
      static byte[] toBytes​(Fp12 z)
      Serialize a G_T element to bytes per GM/T 0044.5: high dimension first, recursively over the 1-2-4-12 tower (w^2, w^1, w^0; then v^1, v^0; then u^1, u^0), 32 bytes per F_q component; 384 bytes total.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • pairing

        public static Fp12 pairing​(ECPoint p,
                           SM9G2Point q)
        e(P, Q) for P in G1 (a point of E(F_q)) and Q in G2 (a point of the twist).

      • toBytes

        public static byte[] toBytes​(Fp12 z)
        Serialize a G_T element to bytes per GM/T 0044.5: high dimension first, recursively over the 1-2-4-12 tower (w^2, w^1, w^0; then v^1, v^0; then u^1, u^0), 32 bytes per F_q component; 384 bytes total.