de.flexiprovider.common.math.ellipticcurves
Class EllipticCurve

java.lang.Object
  |
  +--de.flexiprovider.common.math.ellipticcurves.EllipticCurve

Direct Known Subclasses:

EllipticCurveGF2n, EllipticCurveGFP

public abstract class EllipticCurve

extends java.lang.Object

This class is the top-interface for elliptic curves over finite fields. Implemented are those over prime fields GF(p) (EllipticCurveGFP) as well as over characteristic 2 fields GF(2ⁿ)) (EllipticCurveGF2n).

This class stores the size of the underlying field as a FlexiBigInt mQ = p or mQ = 2ⁿ. The curve parameters a and b are stored as instances of GFElement.

Author:

Birgit Henhapl, Martin Döring

See Also:

EllipticCurveGFP, EllipticCurveGF2n, GFElement

Field Summary

protected GFElement	mA curve parameter a
protected GFElement	mB curve parameter b
protected FlexiBigInt	mQ size of the underlying field

Constructor Summary

protected

EllipticCurve(GFElement a, GFElement b, FlexiBigInt q) Construct an elliptic curve E with the specified parameters.

Method Summary

boolean	equals(java.lang.Object other) Compare this curve with another object.
GFElement	getA()
GFElement	getB()
FlexiBigInt	getQ() Returns the size of underlying field p.
int	hashCode()
abstract java.lang.String	toString()

Methods inherited from class java.lang.Object

, clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

mQ

protected FlexiBigInt mQ

size of the underlying field

mA

protected GFElement mA

curve parameter a

mB

protected GFElement mB

curve parameter b

Constructor Detail

EllipticCurve

protected EllipticCurve(GFElement a,
                        GFElement b,
                        FlexiBigInt q)

Construct an elliptic curve E with the specified parameters.

Parameters:

a - curve parameter a

b - curve parameter b

q - size of the underlying field

See Also:

GFElement

Method Detail

getQ

public FlexiBigInt getQ()

Returns the size of underlying field p.

Returns:

characteristic of underlying field p

getA

public GFElement getA()

Returns:

a copy of the elliptic curve parameter a

getB

public GFElement getB()

Returns:

a copy of the elliptic curve parameter b

equals

public boolean equals(java.lang.Object other)

Compare this curve with another object.

Overrides:

equals in class java.lang.Object

Parameters:

other - the other object

Returns:

the result of the comparison

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code of this curve

toString

public abstract java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a human readable form of this elliptic curve