org.spongycastle.pqc.math.linearalgebra

Class GF2nONBField

java.lang.Object

org.spongycastle.pqc.math.linearalgebra.GF2nField

org.spongycastle.pqc.math.linearalgebra.GF2nONBField

public class GF2nONBField
extends GF2nField

This class implements the abstract class GF2nField for ONB representation. It computes the fieldpolynomial, multiplication matrix and one of its roots mONBRoot, (see for example Certicoms Whitepapers). GF2nField is used by GF2nONBElement which implements the elements of this field.

See Also:

GF2nField, GF2nONBElement

Field Summary

Fields inherited from class org.spongycastle.pqc.math.linearalgebra.GF2nField

fieldPolynomial, fields, matrices, mDegree, random

Constructor Summary

Constructors

Constructor and Description
GF2nONBField(int deg, java.security.SecureRandom random) constructs an instance of the finite field with 2deg elements and characteristic 2.

Method Summary

Modifier and Type	Method and Description
protected void	computeCOBMatrix(GF2nField B1) Computes the change-of-basis matrix for basis conversion according to 1363.
protected void	computeFieldPolynomial() Computes the field polynomial for a ONB according to IEEE 1363 A.7.2 (p110f).
protected GF2nElement	getRandomRoot(GF2Polynomial polynomial) Computes a random root of the given polynomial.

Methods inherited from class org.spongycastle.pqc.math.linearalgebra.GF2nField

convert, equals, getDegree, getFieldPolynomial, hashCode, invertMatrix

Methods inherited from class java.lang.Object

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

Constructor Detail

GF2nONBField

public GF2nONBField(int deg,
                    java.security.SecureRandom random)
             throws java.lang.RuntimeException

constructs an instance of the finite field with 2^deg elements and characteristic 2.

Parameters:

deg - -the extention degree of this field

random - - a source of randomness for generating polynomials on the field.

Throws:

java.lang.RuntimeException

Method Detail

getRandomRoot

protected GF2nElement getRandomRoot(GF2Polynomial polynomial)

Computes a random root of the given polynomial.

Specified by:

getRandomRoot in class GF2nField

Parameters:

polynomial - a polynomial

Returns:

a random root of the polynomial

See Also:

"P1363 A.5.6, p103f"

computeCOBMatrix

protected void computeCOBMatrix(GF2nField B1)

Computes the change-of-basis matrix for basis conversion according to 1363. The result is stored in the lists fields and matrices.

Specified by:

computeCOBMatrix in class GF2nField

Parameters:

B1 - the GF2nField to convert to

See Also:

"P1363 A.7.3, p111ff"

computeFieldPolynomial

protected void computeFieldPolynomial()

Computes the field polynomial for a ONB according to IEEE 1363 A.7.2 (p110f).

Specified by:

computeFieldPolynomial in class GF2nField

See Also:

"P1363 A.7.2, p110f"