Examples with ECFieldElement com.github.zhenwei.core.math.ec.ECFieldElement used on opensource projects

Example 96 with ECFieldElement

use of com.github.zhenwei.core.math.ec.ECFieldElement in project LinLong-Java by zhenwei1108.

the class SecT409R1Point method getCompressionYTilde.

protected boolean getCompressionYTilde() {
    ECFieldElement X = this.getRawXCoord();
    if (X.isZero()) {
        return false;
    }
    ECFieldElement Y = this.getRawYCoord();
    // Y is actually Lambda (X + Y/X) here
    return Y.testBitZero() != X.testBitZero();
}

Example 97 with ECFieldElement

use of com.github.zhenwei.core.math.ec.ECFieldElement in project LinLong-Java by zhenwei1108.

the class SecT571K1Point method twicePlus.

public ECPoint twicePlus(ECPoint b) {
    if (this.isInfinity()) {
        return b;
    }
    if (b.isInfinity()) {
        return twice();
    }
    ECCurve curve = this.getCurve();
    ECFieldElement X1 = this.x;
    if (X1.isZero()) {
        // A point with X == 0 is its own additive inverse
        return b;
    }
    // NOTE: twicePlus() only optimized for lambda-affine argument
    ECFieldElement X2 = b.getRawXCoord(), Z2 = b.getZCoord(0);
    if (X2.isZero() || !Z2.isOne()) {
        return twice().add(b);
    }
    ECFieldElement L1 = this.y, Z1 = this.zs[0];
    ECFieldElement L2 = b.getRawYCoord();
    ECFieldElement X1Sq = X1.square();
    ECFieldElement L1Sq = L1.square();
    ECFieldElement Z1Sq = Z1.square();
    ECFieldElement L1Z1 = L1.multiply(Z1);
    ECFieldElement T = L1Sq.add(L1Z1);
    ECFieldElement L2plus1 = L2.addOne();
    ECFieldElement A = L2plus1.multiply(Z1Sq).add(L1Sq).multiplyPlusProduct(T, X1Sq, Z1Sq);
    ECFieldElement X2Z1Sq = X2.multiply(Z1Sq);
    ECFieldElement B = X2Z1Sq.add(T).square();
    if (B.isZero()) {
        if (A.isZero()) {
            return b.twice();
        }
        return curve.getInfinity();
    }
    if (A.isZero()) {
        return new SecT571K1Point(curve, A, curve.getB());
    }
    ECFieldElement X3 = A.square().multiply(X2Z1Sq);
    ECFieldElement Z3 = A.multiply(B).multiply(Z1Sq);
    ECFieldElement L3 = A.add(B).square().multiplyPlusProduct(T, L2plus1, Z3);
    return new SecT571K1Point(curve, X3, L3, new ECFieldElement[] { Z3 });
}

Example 98 with ECFieldElement

use of com.github.zhenwei.core.math.ec.ECFieldElement in project LinLong-Java by zhenwei1108.

the class SecT571K1Point method getYCoord.

public ECFieldElement getYCoord() {
    ECFieldElement X = x, L = y;
    if (this.isInfinity() || X.isZero()) {
        return L;
    }
    // Y is actually Lambda (X + Y/X) here; convert to affine value on the fly
    ECFieldElement Y = L.add(X).multiply(X);
    ECFieldElement Z = zs[0];
    if (!Z.isOne()) {
        Y = Y.divide(Z);
    }
    return Y;
}

Example 99 with ECFieldElement

use of com.github.zhenwei.core.math.ec.ECFieldElement in project LinLong-Java by zhenwei1108.

the class SecT571K1Point method getCompressionYTilde.

protected boolean getCompressionYTilde() {
    ECFieldElement X = this.getRawXCoord();
    if (X.isZero()) {
        return false;
    }
    ECFieldElement Y = this.getRawYCoord();
    // Y is actually Lambda (X + Y/X) here
    return Y.testBitZero() != X.testBitZero();
}

Example 100 with ECFieldElement

use of com.github.zhenwei.core.math.ec.ECFieldElement in project LinLong-Java by zhenwei1108.

the class SecT571K1Point method add.

public ECPoint add(ECPoint b) {
    if (this.isInfinity()) {
        return b;
    }
    if (b.isInfinity()) {
        return this;
    }
    ECCurve curve = this.getCurve();
    SecT571FieldElement X1 = (SecT571FieldElement) this.x;
    SecT571FieldElement X2 = (SecT571FieldElement) b.getRawXCoord();
    if (X1.isZero()) {
        if (X2.isZero()) {
            return curve.getInfinity();
        }
        return b.add(this);
    }
    SecT571FieldElement L1 = (SecT571FieldElement) this.y, Z1 = (SecT571FieldElement) this.zs[0];
    SecT571FieldElement L2 = (SecT571FieldElement) b.getRawYCoord(), Z2 = (SecT571FieldElement) b.getZCoord(0);
    long[] t1 = Nat576.create64();
    long[] t2 = Nat576.create64();
    long[] t3 = Nat576.create64();
    long[] t4 = Nat576.create64();
    long[] Z1Precomp = Z1.isOne() ? null : SecT571Field.precompMultiplicand(Z1.x);
    long[] U2, S2;
    if (Z1Precomp == null) {
        U2 = X2.x;
        S2 = L2.x;
    } else {
        SecT571Field.multiplyPrecomp(X2.x, Z1Precomp, U2 = t2);
        SecT571Field.multiplyPrecomp(L2.x, Z1Precomp, S2 = t4);
    }
    long[] Z2Precomp = Z2.isOne() ? null : SecT571Field.precompMultiplicand(Z2.x);
    long[] U1, S1;
    if (Z2Precomp == null) {
        U1 = X1.x;
        S1 = L1.x;
    } else {
        SecT571Field.multiplyPrecomp(X1.x, Z2Precomp, U1 = t1);
        SecT571Field.multiplyPrecomp(L1.x, Z2Precomp, S1 = t3);
    }
    long[] A = t3;
    SecT571Field.add(S1, S2, A);
    long[] B = t4;
    SecT571Field.add(U1, U2, B);
    if (Nat576.isZero64(B)) {
        if (Nat576.isZero64(A)) {
            return twice();
        }
        return curve.getInfinity();
    }
    SecT571FieldElement X3, L3, Z3;
    if (X2.isZero()) {
        // TODO This can probably be optimized quite a bit
        ECPoint p = this.normalize();
        X1 = (SecT571FieldElement) p.getXCoord();
        ECFieldElement Y1 = p.getYCoord();
        ECFieldElement Y2 = L2;
        ECFieldElement L = Y1.add(Y2).divide(X1);
        X3 = (SecT571FieldElement) L.square().add(L).add(X1);
        if (X3.isZero()) {
            return new SecT571K1Point(curve, X3, curve.getB());
        }
        ECFieldElement Y3 = L.multiply(X1.add(X3)).add(X3).add(Y1);
        L3 = (SecT571FieldElement) Y3.divide(X3).add(X3);
        Z3 = (SecT571FieldElement) curve.fromBigInteger(ECConstants.ONE);
    } else {
        SecT571Field.square(B, B);
        long[] APrecomp = SecT571Field.precompMultiplicand(A);
        long[] AU1 = t1;
        long[] AU2 = t2;
        SecT571Field.multiplyPrecomp(U1, APrecomp, AU1);
        SecT571Field.multiplyPrecomp(U2, APrecomp, AU2);
        X3 = new SecT571FieldElement(t1);
        SecT571Field.multiply(AU1, AU2, X3.x);
        if (X3.isZero()) {
            return new SecT571K1Point(curve, X3, curve.getB());
        }
        Z3 = new SecT571FieldElement(t3);
        SecT571Field.multiplyPrecomp(B, APrecomp, Z3.x);
        if (Z2Precomp != null) {
            SecT571Field.multiplyPrecomp(Z3.x, Z2Precomp, Z3.x);
        }
        long[] tt = Nat576.createExt64();
        SecT571Field.add(AU2, B, t4);
        SecT571Field.squareAddToExt(t4, tt);
        SecT571Field.add(L1.x, Z1.x, t4);
        SecT571Field.multiplyAddToExt(t4, Z3.x, tt);
        L3 = new SecT571FieldElement(t4);
        SecT571Field.reduce(tt, L3.x);
        if (Z1Precomp != null) {
            SecT571Field.multiplyPrecomp(Z3.x, Z1Precomp, Z3.x);
        }
    }
    return new SecT571K1Point(curve, X3, L3, new ECFieldElement[] { Z3 });
}