public void testInvariants() {
BigInteger a1 = BigInteger.ZERO;
BigInteger a2 = BigInteger.ZERO;
BigInteger a3 = BigInteger.ONE;
BigInteger a4 = BigInteger.ONE.negate();
BigInteger a6 = BigInteger.ZERO;
FiniteFieldPrime field = new FiniteFieldPrime(new BigInteger("751"));
CubicCurve curve = new CubicCurve(a1, a2, a3, a4, a6, field);
assertTrue(curve.b2().compareTo(BigInteger.ZERO) == 0);
assertTrue(curve.b4().compareTo(new BigInteger("749")) == 0);
assertTrue(curve.b6().compareTo(new BigInteger("1")) == 0);
assertTrue(curve.b8().compareTo(new BigInteger("750")) == 0);
assertTrue(curve.c4().compareTo(new BigInteger("48")) == 0);
assertTrue(curve.c6().compareTo(new BigInteger("535")) == 0);
assertTrue(curve.discriminant().compareTo(new BigInteger("37")) == 0);
assertTrue(curve.j().compareTo(new BigInteger("533")) == 0);
}
public void testToString() {
BigInteger a1 = new BigInteger("7");
BigInteger a2 = new BigInteger("2");
BigInteger a3 = new BigInteger("91");
BigInteger a4 = new BigInteger("12");
BigInteger a6 = new BigInteger("54");
FiniteFieldPrime field = new FiniteFieldPrime(new BigInteger("93"));
CubicCurve curve = new CubicCurve(a1, a2, a3, a4, a6, field);
String str = curve.toString();
assertTrue(str != null && str.length() > 0);
assertTrue(str.equals("y2 + 7xy + 91y = x3 + 2x2 + 12x + 54"));
}
public void testGet() {
BigInteger a1 = new BigInteger("7");
BigInteger a2 = new BigInteger("2");
BigInteger a3 = new BigInteger("91");
BigInteger a4 = new BigInteger("12");
BigInteger a6 = new BigInteger("54");
FiniteFieldPrime field = new FiniteFieldPrime(new BigInteger("93"));
CubicCurve curve = new CubicCurve(a1, a2, a3, a4, a6, field);
assertTrue(curve != null);
assertTrue(a1.compareTo(curve.a1()) == 0 && a1 != curve.a1());
assertTrue(a2.compareTo(curve.a2()) == 0 && a2 != curve.a2());
assertTrue(a3.compareTo(curve.a3()) == 0 && a3 != curve.a3());
assertTrue(a4.compareTo(curve.a4()) == 0 && a4 != curve.a4());
assertTrue(a6.compareTo(curve.a6()) == 0 && a6 != curve.a6());
assertTrue(field.equals(curve.getField()) && field != curve.getField());
}
public void testIsomorphism() {
try {
CubicCurve.isomorphism(null);
assertTrue(false);
} catch (NullPointerException npe) {
assertTrue(true);
}
// char != 2,3
BigInteger a1 = BigInteger.ZERO;
BigInteger a2 = BigInteger.ZERO;
BigInteger a3 = BigInteger.ONE;
BigInteger a4 = BigInteger.ONE.negate();
BigInteger a6 = BigInteger.ZERO;
Field field = new FiniteFieldPrime(new BigInteger("751"));
CubicCurve curve = new CubicCurve(a1, a2, a3, a4, a6, field);
CubicCurve c2 = CubicCurve.isomorphism(curve);
assertTrue(curve != c2);
assertTrue(c2.a1().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a2().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a3().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a4().compareTo(new BigInteger("750")) == 0);
assertTrue(c2.a6().compareTo(new BigInteger("188")) == 0);
// char = 2, a1 = 0
a1 = BigInteger.ZERO;
a2 = BigInteger.ONE;
a3 = BigInteger.ONE;
a4 = BigInteger.ZERO;
a6 = BigInteger.ONE;
field = new FiniteFieldCharTwo(new BigInteger("11"));
curve = new CubicCurve(a1, a2, a3, a4, a6, field);
c2 = CubicCurve.isomorphism(curve);
assertTrue(curve != c2);
assertTrue(c2.a1().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a2().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a3().compareTo(BigInteger.ONE) == 0);
assertTrue(c2.a4().compareTo(BigInteger.ONE) == 0);
assertTrue(c2.a6().compareTo(BigInteger.ONE) == 0);
// char = 2, a1 != 0
a1 = BigInteger.ONE;
a2 = BigInteger.ONE;
a3 = BigInteger.ZERO;
a4 = BigInteger.ONE;
a6 = BigInteger.ONE;
field = new FiniteFieldCharTwo(new BigInteger("11"));
curve = new CubicCurve(a1, a2, a3, a4, a6, field);
c2 = CubicCurve.isomorphism(curve);
assertTrue(curve != c2);
assertTrue(c2.a1().compareTo(BigInteger.ONE) == 0);
assertTrue(c2.a2().compareTo(BigInteger.ONE) == 0);
assertTrue(c2.a3().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a4().compareTo(BigInteger.ZERO) == 0);
assertTrue(c2.a6().compareTo(BigInteger.ZERO) == 0);
/* test removed until field char 3 implemented
// char = 3, d2 != 0
a1 = new BigInteger( "2" );
a2 = new BigInteger( "0" );
a3 = new BigInteger( "0" );
a4 = new BigInteger( "2" );
a6 = new BigInteger( "1" );
field = new FiniteFieldCharThree( new BigInteger( "11" ) );
curve = new CubicCurve( a1, a2, a3, a4, a6, field );
c2 = CubicCurve.isomorphism( curve );
assertTrue( curve != c2 );
assertTrue( c2.a1().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a2().compareTo( BigInteger.ONE ) == 0 );
assertTrue( c2.a3().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a4().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a6().compareTo( new BigInteger( "2" ) ) == 0 );
// char = 3, d2 = 0
a1 = new BigInteger( "0" );
a2 = new BigInteger( "0" );
a3 = new BigInteger( "2" );
a4 = new BigInteger( "2" );
a6 = new BigInteger( "1" );
field = new FiniteFieldCharThree( new BigInteger( "11" ) );
curve = new CubicCurve( a1, a2, a3, a4, a6, field );
c2 = CubicCurve.isomorphism( curve );
assertTrue( curve != c2 );
assertTrue( c2.a1().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a2().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a3().compareTo( BigInteger.ZERO ) == 0 );
assertTrue( c2.a4().compareTo( new BigInteger( "2" ) ) == 0 );
assertTrue( c2.a6().compareTo( new BigInteger( "2" ) ) == 0 );
*/
}
