コード例 #1
0
        /* GLV method */
        public static BIG[] Glv(BIG e)
        {
            BIG[] u = new BIG[2];
            if (ECP.CURVE_PAIRING_TYPE == ECP.BN)
            {
                int i, j;
                BIG t = new BIG(0);
                BIG q = new BIG(ROM.CURVE_Order);

                BIG[] v = new BIG[2];
                for (i = 0; i < 2; i++)
                {
                    t.Copy(new BIG(ROM.CURVE_W[i])); // why not just t=new BIG(ROM.CURVE_W[i]);
                    DBIG d = BIG.Mul(t, e);
                    v[i] = new BIG(d.Div(q));
                    u[i] = new BIG(0);
                }

                u[0].Copy(e);
                for (i = 0; i < 2; i++)
                {
                    for (j = 0; j < 2; j++)
                    {
                        t.Copy(new BIG(ROM.CURVE_SB[j][i]));
                        t.Copy(BIG.ModMul(v[j], t, q));
                        u[i].Add(q);
                        u[i].Sub(t);
                        u[i].Mod(q);
                    }
                }
            }
            else
            {
                // -(x^2).P = (Beta.x,y)
                BIG q  = new BIG(ROM.CURVE_Order);
                BIG x  = new BIG(ROM.CURVE_Bnx);
                BIG x2 = BIG.SMul(x, x);
                u[0] = new BIG(e);
                u[0].Mod(x2);
                u[1] = new BIG(e);
                u[1].Div(x2);
                u[1].RSub(q);
            }

            return(u);
        }