EllipticCurve

public class EllipticCurve extends Object

This immutable class holds the necessary values needed to represent an elliptic curve.

Public Constructor Summary

EllipticCurve(ECField field, BigInteger a, BigInteger b)
Creates an elliptic curve with the specified elliptic field field and the coefficients a and b.
EllipticCurve(ECField field, BigInteger a, BigInteger b, byte[] seed)
Creates an elliptic curve with the specified elliptic field field, the coefficients a and b, and the seed used for curve generation.

Public Method Summary

boolean
equals(Object obj)
Compares this elliptic curve for equality with the specified object.
BigInteger
getA()
Returns the first coefficient a of the elliptic curve.
BigInteger
getB()
Returns the second coefficient b of the elliptic curve.
ECField
getField()
Returns the finite field field that this elliptic curve is over.
byte[]
getSeed()
Returns the seeding bytes seed used during curve generation.
int
hashCode()
Returns a hash code value for this elliptic curve.

Inherited Method Summary

Public Constructors

public EllipticCurve (ECField field, BigInteger a, BigInteger b)

Creates an elliptic curve with the specified elliptic field field and the coefficients a and b.

Parameters
field the finite field that this elliptic curve is over.
a the first coefficient of this elliptic curve.
b the second coefficient of this elliptic curve.
Throws
NullPointerException if field, a, or b is null.
IllegalArgumentException if a or b is not null and not in field.

public EllipticCurve (ECField field, BigInteger a, BigInteger b, byte[] seed)

Creates an elliptic curve with the specified elliptic field field, the coefficients a and b, and the seed used for curve generation.

Parameters
field the finite field that this elliptic curve is over.
a the first coefficient of this elliptic curve.
b the second coefficient of this elliptic curve.
seed the bytes used during curve generation for later validation. Contents of this array are copied to protect against subsequent modification.
Throws
NullPointerException if field, a, or b is null.
IllegalArgumentException if a or b is not null and not in field.

Public Methods

public boolean equals (Object obj)

Compares this elliptic curve for equality with the specified object.

Parameters
obj the object to be compared.
Returns
  • true if obj is an instance of EllipticCurve and the field, A, and B match, false otherwise.

public BigInteger getA ()

Returns the first coefficient a of the elliptic curve.

Returns
  • the first coefficient a.

public BigInteger getB ()

Returns the second coefficient b of the elliptic curve.

Returns
  • the second coefficient b.

public ECField getField ()

Returns the finite field field that this elliptic curve is over.

Returns
  • the field field that this curve is over.

public byte[] getSeed ()

Returns the seeding bytes seed used during curve generation. May be null if not specified.

Returns
  • the seeding bytes seed. A new array is returned each time this method is called.

public int hashCode ()

Returns a hash code value for this elliptic curve.

Returns
  • a hash code value computed from the hash codes of the field, A, and B, as follows: (field.hashCode() << 6) + (a.hashCode() << 4) + (b.hashCode() << 2)