Package org.bouncycastle.pqc.math.linearalgebra

Class GF2mMatrix

  • public class GF2mMatrix
extends Matrix
    This class describes some operations with matrices over finite field GF(2m) with small m (1< m <32).
    See Also:
    Matrix

    • Field Detail

      • field

        protected GF2mField field
        finite field GF(2^m)

      • matrix

        protected int[][] matrix
        For the matrix representation the array of type int[][] is used, thus every element of the array keeps one element of the matrix (element from finite field GF(2^m))

    • Constructor Detail

      • GF2mMatrix

        public GF2mMatrix​(GF2mField field,
                  byte[] enc)
        Constructor.
        Parameters:
        field - a finite field GF(2^m)
        enc - byte[] matrix in byte array form

      • GF2mMatrix

        public GF2mMatrix​(GF2mMatrix other)
        Copy constructor.
        Parameters:
        other - another GF2mMatrix

      • GF2mMatrix

        protected GF2mMatrix​(GF2mField field,
                     int[][] matrix)
        Constructor.
        Parameters:
        field - a finite field GF(2^m)
        matrix - the matrix as int array. Only the reference is copied.

    • Method Detail

      • getEncoded

        public byte[] getEncoded()
        Specified by:
        getEncoded in class Matrix
        Returns:
        a byte array encoding of this matrix

      • isZero

        public boolean isZero()
        Check if this is the zero matrix (i.e., all entries are zero).
        Specified by:
        isZero in class Matrix
        Returns:
        true if this is the zero matrix

      • computeInverse

        public Matrix computeInverse()
        Compute the inverse of this matrix.
        Specified by:
        computeInverse in class Matrix
        Returns:
        the inverse of this matrix (newly created).

      • rightMultiply

        public Matrix rightMultiply​(Matrix a)
        Description copied from class: Matrix
        Compute the product of this matrix and another matrix.
        Specified by:
        rightMultiply in class Matrix
        Parameters:
        a - the other matrix
        Returns:
        this * a (newly created)

      • rightMultiply

        public Matrix rightMultiply​(Permutation perm)
        Description copied from class: Matrix
        Compute the product of this matrix and a permutation.
        Specified by:
        rightMultiply in class Matrix
        Parameters:
        perm - the permutation
        Returns:
        this * p (newly created)

      • leftMultiply

        public Vector leftMultiply​(Vector vector)
        Description copied from class: Matrix
        Compute the product of a vector and this matrix. If the length of the vector is greater than the number of rows of this matrix, the matrix is multiplied by each m-bit part of the vector.
        Specified by:
        leftMultiply in class Matrix
        Parameters:
        vector - a vector
        Returns:
        vector * this (newly created)

      • rightMultiply

        public Vector rightMultiply​(Vector vector)
        Description copied from class: Matrix
        Compute the product of this matrix and a vector.
        Specified by:
        rightMultiply in class Matrix
        Parameters:
        vector - a vector
        Returns:
        this * vector (newly created)

      • equals

        public boolean equals​(java.lang.Object other)
        Checks if given object is equal to this matrix. The method returns false whenever the given object is not a matrix over GF(2^m).
        Overrides:
        equals in class java.lang.Object
        Parameters:
        other - object
        Returns:
        true or false

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • toString

        public java.lang.String toString()
        Specified by:
        toString in class Matrix
        Returns:
        a human readable form of the matrix.