EllipticCurve (Java SE 9 & JDK 9 ) (original) (raw)

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	Description
EllipticCurve(ECField field,BigInteger a,BigInteger b)	Creates an elliptic curve with the specified elliptic fieldfield and the coefficients a andb.
EllipticCurve(ECField field,BigInteger a,BigInteger b, byte[] seed)	Creates an elliptic curve with the specified elliptic fieldfield, the coefficients a andb, and the seed used for curve generation.

Method Summary

All Methods Instance Methods Concrete 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](../../../java/lang/Object.html "class in java.lang")  
   `[clone](../../../java/lang/Object.html#clone--), [finalize](../../../java/lang/Object.html#finalize--), [getClass](../../../java/lang/Object.html#getClass--), [notify](../../../java/lang/Object.html#notify--), [notifyAll](../../../java/lang/Object.html#notifyAll--), [toString](../../../java/lang/Object.html#toString--), [wait](../../../java/lang/Object.html#wait--), [wait](../../../java/lang/Object.html#wait-long-), [wait](../../../java/lang/Object.html#wait-long-int-)`

Constructor Detail

 * #### EllipticCurve  
 public EllipticCurve([ECField](../../../java/security/spec/ECField.html "interface in java.security.spec") field,  
                      [BigInteger](../../../java/math/BigInteger.html "class in java.math") a,  
                      [BigInteger](../../../java/math/BigInteger.html "class in java.math") 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](../../../java/lang/NullPointerException.html "class in java.lang")` \- if `field`,`a`, or `b` is null.  
 `[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `a` or `b` is not null and not in `field`.  
 * #### EllipticCurve  
 public EllipticCurve([ECField](../../../java/security/spec/ECField.html "interface in java.security.spec") field,  
                      [BigInteger](../../../java/math/BigInteger.html "class in java.math") a,  
                      [BigInteger](../../../java/math/BigInteger.html "class in java.math") 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](../../../java/lang/NullPointerException.html "class in java.lang")` \- if `field`,`a`, or `b` is null.  
 `[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `a` or `b` is not null and not in `field`.

Method Detail

* #### getField  
public [ECField](../../../java/security/spec/ECField.html "interface in java.security.spec") getField()  
Returns the finite field `field` that this elliptic curve is over.  
Returns:  
the field `field` that this curve is over.  
* #### getA  
public [BigInteger](../../../java/math/BigInteger.html "class in java.math") getA()  
Returns the first coefficient `a` of the elliptic curve.  
Returns:  
the first coefficient `a`.  
* #### getB  
public [BigInteger](../../../java/math/BigInteger.html "class in java.math") 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](../../../java/lang/Object.html "class in java.lang") obj)  
Compares this elliptic curve for equality with the specified object.  
Overrides:  
`[equals](../../../java/lang/Object.html#equals-java.lang.Object-)` in class `[Object](../../../java/lang/Object.html "class in java.lang")`  
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()](../../../java/lang/Object.html#hashCode--), [HashMap](../../../java/util/HashMap.html "class in java.util")  
* #### hashCode  
public int hashCode()  
Returns a hash code value for this elliptic curve.  
Overrides:  
`[hashCode](../../../java/lang/Object.html#hashCode--)` in class `[Object](../../../java/lang/Object.html "class in java.lang")`  
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)](../../../java/lang/Object.html#equals-java.lang.Object-), [System.identityHashCode(java.lang.Object)](../../../java/lang/System.html#identityHashCode-java.lang.Object-)

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EllipticCurve (Java SE 9 & JDK 9 ) (original) (raw)

Constructor Summary

Method Summary

Constructor Detail

Method Detail