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org.bouncycastle.pqc.legacy.math.linearalgebra

public Class PolynomialRingGF2m

Class Inheritance

extends Object

java.lang.Object
org.bouncycastle.pqc.legacy.math.linearalgebra.PolynomialRingGF2m

This class represents polynomial rings GF(2^m)[X]/p(X) for m<32. If p(X) is irreducible, the polynomial ring is in fact an extension field of GF(2^m).

Field Summary

Modifier and Type	Field and Description
private GF2mField	field the finite field this polynomial ring is defined over
private PolynomialGF2mSmallM	p the reduction polynomial
protected PolynomialGF2mSmallM[]	sqMatrix the squaring matrix for this polynomial ring (given as the array of its row vectors)
protected PolynomialGF2mSmallM[]	sqRootMatrix the matrix for computing square roots in this polynomial ring (given as the array of its row vectors).

Constructor Summary

Access	Constructor and Description
public	PolynomialRingGF2m(GF2mField the finite field field, PolynomialGF2mSmallM the reduction polynomial p) Constructor.

Method Summary

Modifier and Type	Method and Description
private void	computeSquareRootMatrix() Compute the matrix for computing square roots in this polynomial ring by inverting the squaring matrix.
private void	computeSquaringMatrix() Compute the squaring matrix for this polynomial ring, using the base field and the reduction polynomial.
public PolynomialGF2mSmallM[]	Returns: the matrix for computing square roots for this polynomial ring getSquareRootMatrix()
public PolynomialGF2mSmallM[]	Returns: the squaring matrix for this polynomial ring getSquaringMatrix()
private static void	swapColumns(PolynomialGF2mSmallM[] matrix, int first, int second)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

field	back to summary
private GF2mField field the finite field this polynomial ring is defined over

p	back to summary
private PolynomialGF2mSmallM p the reduction polynomial

sqMatrix	back to summary
protected PolynomialGF2mSmallM[] sqMatrix the squaring matrix for this polynomial ring (given as the array of its row vectors)

sqRootMatrix	back to summary
protected PolynomialGF2mSmallM[] sqRootMatrix the matrix for computing square roots in this polynomial ring (given as the array of its row vectors). This matrix is computed as the inverse of the squaring matrix.

Constructor Detail

PolynomialRingGF2m

back to summary

public PolynomialRingGF2m(GF2mField field, PolynomialGF2mSmallM p)

Constructor.

Parameters

field:GF2mField: the finite field
p:PolynomialGF2mSmallM: the reduction polynomial

Method Detail

computeSquareRootMatrix	back to summary
private void computeSquareRootMatrix() Compute the matrix for computing square roots in this polynomial ring by inverting the squaring matrix.

computeSquaringMatrix	back to summary
private void computeSquaringMatrix() Compute the squaring matrix for this polynomial ring, using the base field and the reduction polynomial.

getSquareRootMatrix	back to summary
public PolynomialGF2mSmallM[] getSquareRootMatrix() Returns:PolynomialGF2mSmallM[] the matrix for computing square roots for this polynomial ring

getSquaringMatrix	back to summary
public PolynomialGF2mSmallM[] getSquaringMatrix() Returns:PolynomialGF2mSmallM[] the squaring matrix for this polynomial ring

swapColumns	back to summary
private static void swapColumns(PolynomialGF2mSmallM[] matrix, int first, int second)