public class EllipticCurve
extends Object 

Since:

1.5

See Also:

ECField, ECFieldFp, ECFieldF2m

• Constructor Summary

  Constructors

  Constructor	Description
  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.

• Method Summary

  All Methods

  Modifier and Type	Method	Description
  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.

  • Methods inherited from class java.lang.Object

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

• Constructor Detail

  • EllipticCurve

    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.

  • EllipticCurve

    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.

• Method Detail

  • getField

    public ECField getField()

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

    Returns:

    the field field that this curve is over.

  • getA

    public BigInteger getA()

    Returns the first coefficient a of the elliptic curve.

    Returns:

    the first coefficient a.

  • getB

    public BigInteger getB()

    Returns the second coefficient b of the elliptic curve.

    Returns:

    the second coefficient b.

  • getSeed

    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.

  • equals

    public boolean equals(Object obj)

    Compares this elliptic curve for equality with the specified object.

    Overrides:

    equals in class 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.

    See Also:

    Object.hashCode(), HashMap

  • hashCode

    public int hashCode()

    Returns a hash code value for this elliptic curve.

    Overrides:

    hashCode in class Object

    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)
     

    See Also:

    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)