EllipticCurve (Java Platform SE 7 b138)

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:
ECField, ECFieldFp, ECFieldF2m

Constructor Summary

Constructors
Constructor and 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

Methods
Modifier and Type	Method and 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, B, and seeding bytes 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.
    See Also:
    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

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For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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DRAFT ea-b138

Class EllipticCurve

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

EllipticCurve

EllipticCurve

Method Detail

getField

getA

getB

getSeed

equals

hashCode