Class ECPoint

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.

Since:
1.5

Field Summary

Fields
Modifier and Type Field Description
static ECPoint POINT_INFINITY

This defines the point at infinity.

Constructor Summary

Constructors
Constructor Description
ECPoint​(BigInteger x, BigInteger y)

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

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description
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.

Methods declared in class java.lang.Object

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

Field Detail

POINT_INFINITY

public static final ECPoint POINT_INFINITY

This defines the point at infinity.

Constructor Detail

ECPoint

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.

Method Detail

getAffineX

public BigInteger getAffineX()

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

Returns:
the affine x-coordinate.

getAffineY

public BigInteger getAffineY()

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

Returns:
the affine y-coordinate.

equals

public boolean equals​(Object obj)

Compares this elliptic curve point 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 ECPoint and the affine coordinates match, false otherwise.
See Also:
Object.hashCode(), HashMap

hashCode

public int hashCode()

Returns a hash code value for this elliptic curve point.

Overrides:
hashCode in class Object
Returns:
a hash code value.
See Also:
Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)