ECPoint

AI-generated Key Takeaways

• ECPoint is an immutable class representing a point on an elliptic curve using affine coordinates.

• It includes a constant POINT_INFINITY for the point at infinity.

• An ECPoint can be constructed using affine x and y coordinates (BigInteger values).

• Methods are provided to get the affine coordinates and to check for equality with other ECPoint objects.

• It inherits methods from Object for standard object operations like equals, hashCode, and toString.

public class ECPoint extends Object

This immutable class represents a point on an elliptic curve (EC) in affine coordinates. Other coordinate systems can extend this class to represent this point in other coordinates.

Field Summary

public static final ECPoint

POINT_INFINITY

This defines the point at infinity.

Public Constructor Summary

ECPoint(BigInteger x, BigInteger y) Creates an ECPoint from the specified affine x-coordinate x and affine y-coordinate y.

Public Method Summary

boolean	equals(Object obj) Compares this elliptic curve point for equality with the specified object.
BigInteger	getAffineX() Returns the affine x-coordinate x.
BigInteger	getAffineY() Returns the affine y-coordinate y.
int	hashCode() Returns a hash code value for this elliptic curve point.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Fields

public static final ECPoint POINT_INFINITY

This defines the point at infinity.

Public Constructors

public ECPoint (BigInteger x, BigInteger y)

Creates an ECPoint from the specified affine x-coordinate x and affine y-coordinate y.

Parameters

x	the affine x-coordinate.
y	the affine y-coordinate.

Throws

NullPointerException	if x or y is null.

Public Methods

public boolean equals (Object obj)

Compares this elliptic curve point for equality with the specified object.

Parameters

obj	the object to be compared.

Returns

• true if obj is an instance of ECPoint and the affine coordinates match, false otherwise.

public BigInteger getAffineX ()

Returns the affine x-coordinate x. Note: POINT_INFINITY has a null affine x-coordinate.

Returns

• the affine x-coordinate.

public BigInteger getAffineY ()

Returns the affine y-coordinate y. Note: POINT_INFINITY has a null affine y-coordinate.

Returns

• the affine y-coordinate.

public int hashCode ()

Returns a hash code value for this elliptic curve point.

Returns

• a hash code value.