iaik.security.ec.math.curve

Class PrimeWeierstrassCurveFactory

java.lang.Object

iaik.security.ec.math.curve.PrimeWeierstrassCurveFactory

public final class PrimeWeierstrassCurveFactory
extends Object

This general-purpose factory generates prime Weierstrass-type elliptic curves for given parameters.

The user can choose between various coordinate systems, which are listed in PrimeCurveCoordinateTypes. By default a curve using the fastest coordinate type available will be returned.

Author:

Christian Hanser

Method Summary

Modifier and Type	Method and Description
static EllipticCurve	getCurve(AbstractPrimeField field, BigInteger a, BigInteger b) The factory method.
static EllipticCurve	getCurve(AbstractPrimeField field, BigInteger a, BigInteger b, BigInteger order) The factory method.
static EllipticCurve	getCurve(PrimeCurveCoordinateTypes type, AbstractPrimeField field, BigInteger a, BigInteger b) The factory method.
static EllipticCurve	getCurve(PrimeCurveCoordinateTypes type, AbstractPrimeField field, BigInteger a, BigInteger b, BigInteger order, BigInteger beta, BigInteger lambda) The factory method.

Methods inherited from class java.lang.Object

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

Method Detail

getCurve

public static EllipticCurve getCurve(AbstractPrimeField field,
                                     BigInteger a,
                                     BigInteger b)
                              throws InvalidCurveException

The factory method. Returns the curve with the fastest arithmetic for a given coordinate type and given curve parameters.

Parameters:

field - the underlying prime field

a - the first curve parameter

b - the second curve parameter

Returns:

a curve of given type and parameters over the prime field field

Throws:

InvalidCurveException - if the curve is singular

getCurve

public static EllipticCurve getCurve(PrimeCurveCoordinateTypes type,
                                     AbstractPrimeField field,
                                     BigInteger a,
                                     BigInteger b)
                              throws InvalidCurveException

The factory method. Returns the curve with the fastest arithmetic for a given coordinate type and given curve parameters.

Parameters:

type - the coordinate type

field - the underlying prime field

a - the first curve parameter

b - the second curve parameter

Returns:

a curve of given type and parameters over the prime field field

Throws:

InvalidCurveException - if the curve is singular

getCurve

public static EllipticCurve getCurve(PrimeCurveCoordinateTypes type,
                                     AbstractPrimeField field,
                                     BigInteger a,
                                     BigInteger b,
                                     BigInteger order,
                                     BigInteger beta,
                                     BigInteger lambda)
                              throws InvalidCurveException

The factory method. Returns the curve with the fastest arithmetic for a given coordinate type and given curve parameters.

Parameters:

type - the coordinate type

field - the underlying prime field

a - the first curve parameter

b - the second curve parameter

order - the order of the curve group

beta - defines the efficient endomorphism φ, if available

lambda - the eigen value of φ

Returns:

a curve of given type and parameters over the prime field field

Throws:

InvalidCurveException - if the curve is singular

getCurve

public static EllipticCurve getCurve(AbstractPrimeField field,
                                     BigInteger a,
                                     BigInteger b,
                                     BigInteger order)
                              throws InvalidCurveException

The factory method. Returns the curve with the fastest arithmetic for given curve parameters.

Parameters:

field - the underlying prime field

a - the first curve parameter

b - the second curve parameter

order - the order of the associated curve group

Returns:

a curve of given type and parameters over the prime field field

Throws:

InvalidCurveException - if the curve is singular