java.lang.Object
- org.bouncycastle.math.ec.ECFieldElement
- - org.bouncycastle.math.ec.ECFieldElement.AbstractF2m
  - - org.bouncycastle.math.ec.ECFieldElement.F2m

All Implemented Interfaces:

ECConstants

Enclosing class:

ECFieldElement
```
public static class ECFieldElement.F2m
extends ECFieldElement.AbstractF2m
```
Class representing the Elements of the finite field F_2^m in polynomial basis (PB) representation. Both trinomial (TPB) and pentanomial (PPB) polynomial basis representations are supported. Gaussian normal basis (GNB) representation is not supported.

Nested Class Summary
- Nested classes/interfaces inherited from class org.bouncycastle.math.ec.ECFieldElement
  ECFieldElement.AbstractF2m, ECFieldElement.AbstractFp, ECFieldElement.F2m, ECFieldElement.Fp

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`GNB`	Indicates gaussian normal basis representation (GNB).
`static int`	`PPB`	Indicates pentanomial basis representation (PPB).
`static int`	`TPB`	Indicates trinomial basis representation (TPB).

Fields inherited from interface org.bouncycastle.math.ec.ECConstants
EIGHT, FOUR, ONE, THREE, TWO, ZERO

Constructor Summary

Constructors
Constructor Description

F2m(int m, int k1, int k2, int k3, java.math.BigInteger x)
Deprecated.
Use ECCurve.fromBigInteger to construct field elements

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`ECFieldElement`	`add(ECFieldElement b)`
`ECFieldElement`	`addOne()`
`int`	`bitLength()`
`ECFieldElement`	`divide(ECFieldElement b)`
`boolean`	`equals(java.lang.Object anObject)`
`java.lang.String`	`getFieldName()`
`int`	`getFieldSize()`
`int`	`getK1()`
`int`	`getK2()`
`int`	`getK3()`
`int`	`getM()`
`int`	`getRepresentation()`
`int`	`hashCode()`
`ECFieldElement`	`invert()`
`boolean`	`isOne()`
`boolean`	`isZero()`
`ECFieldElement`	`multiply(ECFieldElement b)`
`ECFieldElement`	`multiplyMinusProduct(ECFieldElement b, ECFieldElement x, ECFieldElement y)`
`ECFieldElement`	`multiplyPlusProduct(ECFieldElement b, ECFieldElement x, ECFieldElement y)`
`ECFieldElement`	`negate()`
`ECFieldElement`	`sqrt()`
`ECFieldElement`	`square()`
`ECFieldElement`	`squareMinusProduct(ECFieldElement x, ECFieldElement y)`
`ECFieldElement`	`squarePlusProduct(ECFieldElement x, ECFieldElement y)`
`ECFieldElement`	`squarePow(int pow)`
`ECFieldElement`	`subtract(ECFieldElement b)`
`boolean`	`testBitZero()`
`java.math.BigInteger`	`toBigInteger()`

Methods inherited from class org.bouncycastle.math.ec.ECFieldElement.AbstractF2m
halfTrace, hasFastTrace, trace

Methods inherited from class org.bouncycastle.math.ec.ECFieldElement
getEncoded, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - GNB
```
public static final int GNB
```
    Indicates gaussian normal basis representation (GNB). Number chosen according to X9.62. GNB is not implemented at present.
    
    See Also:
    
    Constant Field Values
  - TPB
```
public static final int TPB
```
    Indicates trinomial basis representation (TPB). Number chosen according to X9.62.
    
    See Also:
    
    Constant Field Values
  - PPB
```
public static final int PPB
```
    Indicates pentanomial basis representation (PPB). Number chosen according to X9.62.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - F2m
```
public F2m(int m,
           int k1,
           int k2,
           int k3,
           java.math.BigInteger x)
```
    Deprecated.
    Use ECCurve.fromBigInteger to construct field elements
    
    Constructor for PPB.
    
    Parameters:
    
    m - The exponent m of F_2^m.
    
    k1 - The integer k1 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
    
    k2 - The integer k2 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
    
    k3 - The integer k3 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
    
    x - The BigInteger representing the value of the field element.
- Method Detail
  - bitLength
```
public int bitLength()
```
    Overrides:
    
    bitLength in class ECFieldElement
  - isOne
```
public boolean isOne()
```
    Overrides:
    
    isOne in class ECFieldElement
  - isZero
```
public boolean isZero()
```
    Overrides:
    
    isZero in class ECFieldElement
  - testBitZero
```
public boolean testBitZero()
```
    Overrides:
    
    testBitZero in class ECFieldElement
  - toBigInteger
```
public java.math.BigInteger toBigInteger()
```
    Specified by:
    
    toBigInteger in class ECFieldElement
  - getFieldName
```
public java.lang.String getFieldName()
```
    Specified by:
    
    getFieldName in class ECFieldElement
  - getFieldSize
```
public int getFieldSize()
```
    Specified by:
    
    getFieldSize in class ECFieldElement
  - add
```
public ECFieldElement add(ECFieldElement b)
```
    Specified by:
    
    add in class ECFieldElement
  - addOne
```
public ECFieldElement addOne()
```
    Specified by:
    
    addOne in class ECFieldElement
  - subtract
```
public ECFieldElement subtract(ECFieldElement b)
```
    Specified by:
    
    subtract in class ECFieldElement
  - multiply
```
public ECFieldElement multiply(ECFieldElement b)
```
    Specified by:
    
    multiply in class ECFieldElement
  - multiplyMinusProduct
```
public ECFieldElement multiplyMinusProduct(ECFieldElement b,
                                           ECFieldElement x,
                                           ECFieldElement y)
```
    Overrides:
    
    multiplyMinusProduct in class ECFieldElement
  - multiplyPlusProduct
```
public ECFieldElement multiplyPlusProduct(ECFieldElement b,
                                          ECFieldElement x,
                                          ECFieldElement y)
```
    Overrides:
    
    multiplyPlusProduct in class ECFieldElement
  - divide
```
public ECFieldElement divide(ECFieldElement b)
```
    Specified by:
    
    divide in class ECFieldElement
  - negate
```
public ECFieldElement negate()
```
    Specified by:
    
    negate in class ECFieldElement
  - square
```
public ECFieldElement square()
```
    Specified by:
    
    square in class ECFieldElement
  - squareMinusProduct
```
public ECFieldElement squareMinusProduct(ECFieldElement x,
                                         ECFieldElement y)
```
    Overrides:
    
    squareMinusProduct in class ECFieldElement
  - squarePlusProduct
```
public ECFieldElement squarePlusProduct(ECFieldElement x,
                                        ECFieldElement y)
```
    Overrides:
    
    squarePlusProduct in class ECFieldElement
  - squarePow
```
public ECFieldElement squarePow(int pow)
```
    Overrides:
    
    squarePow in class ECFieldElement
  - invert
```
public ECFieldElement invert()
```
    Specified by:
    
    invert in class ECFieldElement
  - sqrt
```
public ECFieldElement sqrt()
```
    Specified by:
    
    sqrt in class ECFieldElement
  - getRepresentation
```
public int getRepresentation()
```
    Returns:
    
    the representation of the field F_2^m, either of TPB (trinomial basis representation) or PPB (pentanomial basis representation).
  - getM
```
public int getM()
```
    Returns:
    
    the degree m of the reduction polynomial f(z).
  - getK1
```
public int getK1()
```
    Returns:
    
    TPB: The integer k where x^m + x^k + 1 represents the reduction polynomial f(z).
    PPB: The integer k1 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
  - getK2
```
public int getK2()
```
    Returns:
    
    TPB: Always returns 0
    PPB: The integer k2 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
  - getK3
```
public int getK3()
```
    Returns:
    
    TPB: Always set to 0
    PPB: The integer k3 where x^m + x^k3 + x^k2 + x^k1 + 1 represents the reduction polynomial f(z).
  - equals
```
public boolean equals(java.lang.Object anObject)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object

Class ECFieldElement.F2m

Nested Class Summary

Nested classes/interfaces inherited from class org.bouncycastle.math.ec.ECFieldElement

Field Summary

Fields inherited from interface org.bouncycastle.math.ec.ECConstants

Constructor Summary

Method Summary

Methods inherited from class org.bouncycastle.math.ec.ECFieldElement.AbstractF2m

Methods inherited from class org.bouncycastle.math.ec.ECFieldElement

Methods inherited from class java.lang.Object

Field Detail

GNB

TPB

PPB

Constructor Detail

F2m

Method Detail

bitLength

isOne

isZero

testBitZero

toBigInteger

getFieldName

getFieldSize

add

addOne

subtract

multiply

multiplyMinusProduct

multiplyPlusProduct

divide

negate

square

squareMinusProduct

squarePlusProduct

squarePow

invert

sqrt

getRepresentation

getM

getK1

getK2

getK3

equals

hashCode