Class EllipticCurve

java.lang.Object
java.security.spec.EllipticCurve
public class EllipticCurve extends Object
This immutable class holds the necessary values needed to represent an elliptic curve.
Since:
1.5
See Also:

  • 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

    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 declared in class Object

    clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Creates and returns a copy of this object.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    Finalization is deprecated and subject to removal in a future release.
    final Class<?>
    getClass()
    Returns the runtime class of this Object.
    final void
    notify()
    Wakes up a single thread that is waiting on this object's monitor.
    final void
    notifyAll()
    Wakes up all threads that are waiting on this object's monitor.
    String
    toString()
    Returns a string representation of the object.
    final void
    wait()
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
    final void
    wait(long timeoutMillis)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
    final void
    wait(long timeoutMillis, int nanos)
    Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

  • Constructor Details

    • 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 Details

    • 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:

    • 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: