org.spongycastle.pqc.math.linearalgebra

Class GF2nONBElement

java.lang.Object

org.spongycastle.pqc.math.linearalgebra.GF2nElement

org.spongycastle.pqc.math.linearalgebra.GF2nONBElement

All Implemented Interfaces:

GFElement

public class GF2nONBElement
extends GF2nElement

This class implements an element of the finite field GF(2ⁿ ). It is represented in an optimal normal basis representation and holds the pointer mField to its corresponding field.

See Also:

GF2nField, GF2nElement

Field Summary

Fields inherited from class org.spongycastle.pqc.math.linearalgebra.GF2nElement

mDegree, mField

Constructor Summary

Constructors

Constructor and Description
GF2nONBElement(GF2nONBElement gf2n) Copy constructor.
GF2nONBElement(GF2nONBField gf2n, java.math.BigInteger val) Construct the element of the field gf2n with the specified value val.
GF2nONBElement(GF2nONBField gf2n, byte[] e) Construct a new GF2nONBElement from its encoding.
GF2nONBElement(GF2nONBField gf2n, java.security.SecureRandom rand) Construct a random element over the field gf2n, using the specified source of randomness.

Method Summary

Modifier and Type	Method and Description
GFElement	add(GFElement addend) Compute the sum of this element and addend.
void	addToThis(GFElement addend) Compute this + addend (overwrite this).
java.lang.Object	clone() Create a new GF2nONBElement by cloning this GF2nPolynomialElement.
boolean	equals(java.lang.Object other) Compare this element with another object.
int	hashCode()
GF2nElement	increase() returns this element + 1.
void	increaseThis() increases this element.
GFElement	invert() Compute the multiplicative inverse of this element.
void	invertThis() Multiplicatively invert of this element (overwrite this).
boolean	isOne() Checks whether this element is one.
boolean	isZero() Checks whether this element is zero.
GFElement	multiply(GFElement factor) Compute the product of this element and factor.
void	multiplyThisBy(GFElement factor) Compute this * factor (overwrite this).
static GF2nONBElement	ONE(GF2nONBField gf2n) Create the one element.
GF2nElement	solveQuadraticEquation() Solves a quadratic equation. Let z2 + z = this.
GF2nElement	square() returns this element to the power of 2.
GF2nElement	squareRoot() returns the root ofthis element.
void	squareRootThis() square roots this element.
void	squareThis() squares this element.
boolean	testRightmostBit() Returns whether the highest bit of the bit representation is set
byte[]	toByteArray() Returns this element as byte array.
java.math.BigInteger	toFlexiBigInt() Returns this element as FlexiBigInt.
java.lang.String	toString() Returns a String representation of this element.
java.lang.String	toString(int radix) Returns a String representation of this element.
int	trace() Returns the trace of this element.
static GF2nONBElement	ZERO(GF2nONBField gf2n) Create the zero element.

Methods inherited from class org.spongycastle.pqc.math.linearalgebra.GF2nElement

convert, getField, subtract, subtractFromThis

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

GF2nONBElement

public GF2nONBElement(GF2nONBField gf2n,
                      java.security.SecureRandom rand)

Construct a random element over the field gf2n, using the specified source of randomness.

Parameters:

gf2n - the field

rand - the source of randomness

GF2nONBElement

public GF2nONBElement(GF2nONBField gf2n,
                      byte[] e)

Construct a new GF2nONBElement from its encoding.

Parameters:

gf2n - the field

e - the encoded element

GF2nONBElement

public GF2nONBElement(GF2nONBField gf2n,
                      java.math.BigInteger val)

Construct the element of the field gf2n with the specified value val.

Parameters:

gf2n - the field

val - the value represented by a BigInteger

GF2nONBElement

public GF2nONBElement(GF2nONBElement gf2n)

Copy constructor.

Parameters:

gf2n - the field

Method Detail

clone

public java.lang.Object clone()

Create a new GF2nONBElement by cloning this GF2nPolynomialElement.

Specified by:

clone in interface GFElement

Specified by:

clone in class GF2nElement

Returns:

a copy of this element

ZERO

public static GF2nONBElement ZERO(GF2nONBField gf2n)

Create the zero element.

Parameters:

gf2n - the finite field

Returns:

the zero element in the given finite field

ONE

public static GF2nONBElement ONE(GF2nONBField gf2n)

Create the one element.

Parameters:

gf2n - the finite field

Returns:

the one element in the given finite field

isZero

public boolean isZero()

Checks whether this element is zero.

Returns:

true if this is the zero element

isOne

public boolean isOne()

Checks whether this element is one.

Returns:

true if this is the one element

equals

public boolean equals(java.lang.Object other)

Compare this element with another object.

Specified by:

equals in interface GFElement

Overrides:

equals in class java.lang.Object

Parameters:

other - the other object

Returns:

true if the two objects are equal, false otherwise

hashCode

public int hashCode()

Specified by:

hashCode in interface GFElement

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code of this element

testRightmostBit

public boolean testRightmostBit()

Returns whether the highest bit of the bit representation is set

Specified by:

testRightmostBit in class GF2nElement

Returns:

true, if the highest bit of mPol is set, false, otherwise

add

public GFElement add(GFElement addend)
              throws java.lang.RuntimeException

Compute the sum of this element and addend.

Parameters:

addend - the addend

Returns:

this + other (newly created)

Throws:

java.lang.RuntimeException

addToThis

public void addToThis(GFElement addend)
               throws java.lang.RuntimeException

Compute this + addend (overwrite this).

Parameters:

addend - the addend

Throws:

java.lang.RuntimeException

increase

public GF2nElement increase()

returns this element + 1.

Specified by:

increase in class GF2nElement

Returns:

this + 1

increaseThis

public void increaseThis()

increases this element.

Specified by:

increaseThis in class GF2nElement

multiply

public GFElement multiply(GFElement factor)
                   throws java.lang.RuntimeException

Compute the product of this element and factor.

Parameters:

factor - the factor

Returns:

this * factor (newly created)

Throws:

java.lang.RuntimeException

multiplyThisBy

public void multiplyThisBy(GFElement factor)
                    throws java.lang.RuntimeException

Compute this * factor (overwrite this).

Parameters:

factor - the factor

Throws:

java.lang.RuntimeException

square

public GF2nElement square()

returns this element to the power of 2.

Specified by:

square in class GF2nElement

Returns:

this²

squareThis

public void squareThis()

squares this element.

Specified by:

squareThis in class GF2nElement

invert

public GFElement invert()
                 throws java.lang.ArithmeticException

Compute the multiplicative inverse of this element.

Returns:

this^-1 (newly created)

Throws:

java.lang.ArithmeticException - if this is the zero element.

invertThis

public void invertThis()
                throws java.lang.ArithmeticException

Multiplicatively invert of this element (overwrite this).

Throws:

java.lang.ArithmeticException - if this is the zero element.

squareRoot

public GF2nElement squareRoot()

returns the root ofthis element.

Specified by:

squareRoot in class GF2nElement

Returns:

this^1/2

squareRootThis

public void squareRootThis()

square roots this element.

Specified by:

squareRootThis in class GF2nElement

trace

public int trace()

Returns the trace of this element.

Specified by:

trace in class GF2nElement

Returns:

the trace of this element

solveQuadraticEquation

public GF2nElement solveQuadraticEquation()
                                   throws java.lang.RuntimeException

Solves a quadratic equation.
Let z² + z = this. Then this method returns z.

Specified by:

solveQuadraticEquation in class GF2nElement

Returns:

z with z² + z = this

Throws:

java.lang.RuntimeException

toString

public java.lang.String toString()

Returns a String representation of this element.

Specified by:

toString in interface GFElement

Overrides:

toString in class java.lang.Object

Returns:

String representation of this element with the specified radix

toString

public java.lang.String toString(int radix)

Returns a String representation of this element. radix specifies the radix of the String representation.
NOTE: ONLY radix = 2 or radix = 16 IS IMPLEMENTED

Parameters:

radix - specifies the radix of the String representation

Returns:

String representation of this element with the specified radix

toFlexiBigInt

public java.math.BigInteger toFlexiBigInt()

Returns this element as FlexiBigInt. The conversion is P1363-conform.

Returns:

this element as BigInteger

toByteArray

public byte[] toByteArray()

Returns this element as byte array. The conversion is P1363-conform.

Returns:

this element as byte array