Package org.bouncycastle.pqc.math.linearalgebra

Class GF2nPolynomial

  • public class GF2nPolynomial
extends java.lang.Object
    This class implements polynomials over GF2nElements.
    See Also:
    GF2nElement

    • Constructor Detail

      • GF2nPolynomial

        public GF2nPolynomial​(int deg,
                      GF2nElement elem)
        Creates a new PolynomialGF2n of size deg and elem as coefficients.
        Parameters:
        deg - - the maximum degree + 1
        elem - - a GF2nElement

      • GF2nPolynomial

        public GF2nPolynomial​(GF2nPolynomial a)
        Creates a new PolynomialGF2n by cloning the given PolynomialGF2n a.
        Parameters:
        a - the PolynomialGF2n to clone

      • GF2nPolynomial

        public GF2nPolynomial​(GF2Polynomial polynomial,
                      GF2nField B1)
        Creates a new PolynomialGF2n from the given Bitstring polynomial over the GF2nField B1.
        Parameters:
        polynomial - the Bitstring to use
        B1 - the field

    • Method Detail

      • assignZeroToElements

        public final void assignZeroToElements()

      • size

        public final int size()
        Returns the size (=maximum degree + 1) of this PolynomialGF2n. This is not the degree, use getDegree instead.
        Returns:
        the size (=maximum degree + 1) of this PolynomialGF2n.

      • getDegree

        public final int getDegree()
        Returns the degree of this PolynomialGF2n.
        Returns:
        the degree of this PolynomialGF2n.

      • enlarge

        public final void enlarge​(int k)
        Enlarges the size of this PolynomialGF2n to k + 1.
        Parameters:
        k - the new maximum degree

      • shrink

        public final void shrink()

      • set

        public final void set​(int index,
                      GF2nElement elem)
        Sets the coefficient at index to elem.
        Parameters:
        index - the index
        elem - the GF2nElement to store as coefficient index

      • at

        public final GF2nElement at​(int index)
        Returns the coefficient at index.
        Parameters:
        index - the index
        Returns:
        the GF2nElement stored as coefficient index

      • isZero

        public final boolean isZero()
        Returns true if all coefficients equal zero.
        Returns:
        true if all coefficients equal zero.

      • equals

        public final boolean equals​(java.lang.Object other)
        Overrides:
        equals in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
        Returns:
        the hash code of this polynomial

      • add

        public final GF2nPolynomial add​(GF2nPolynomial b)
        Adds the PolynomialGF2n b to this and returns the result in a new PolynomialGF2n.
        Parameters:
        b - - the PolynomialGF2n to add
        Returns:
        this + b

      • scalarMultiply

        public final GF2nPolynomial scalarMultiply​(GF2nElement s)
        Multiplies the scalar s to each coefficient of this PolynomialGF2n and returns the result in a new PolynomialGF2n.
        Parameters:
        s - the scalar to multiply
        Returns:
        this x s

      • multiply

        public final GF2nPolynomial multiply​(GF2nPolynomial b)
        Multiplies this by b and returns the result in a new PolynomialGF2n.
        Parameters:
        b - the PolynomialGF2n to multiply
        Returns:
        this * b

      • multiplyAndReduce

        public final GF2nPolynomial multiplyAndReduce​(GF2nPolynomial b,
                                              GF2nPolynomial g)
        Multiplies this by b, reduces the result by g and returns it in a new PolynomialGF2n.
        Parameters:
        b - the PolynomialGF2n to multiply
        g - the modul
        Returns:
        this * b mod g

      • reduce

        public final GF2nPolynomial reduce​(GF2nPolynomial g)
                            throws java.lang.RuntimeException,
                                   java.lang.ArithmeticException
        Reduces this by g and returns the result in a new PolynomialGF2n.
        Parameters:
        g - - the modulus
        Returns:
        this % g
        Throws:
        java.lang.RuntimeException
        java.lang.ArithmeticException

      • shiftThisLeft

        public final void shiftThisLeft​(int amount)
        Shifts left this by amount and stores the result in this PolynomialGF2n.
        Parameters:
        amount - the amount to shift the coefficients

      • divide

        public final GF2nPolynomial[] divide​(GF2nPolynomial b)
        Divides this by b and stores the result in a new PolynomialGF2n[2], quotient in result[0] and remainder in result[1].
        Parameters:
        b - the divisor
        Returns:
        the quotient and remainder of this / b

      • remainder

        public final GF2nPolynomial remainder​(GF2nPolynomial b)
                               throws java.lang.RuntimeException,
                                      java.lang.ArithmeticException
        Divides this by b and stores the remainder in a new PolynomialGF2n.
        Parameters:
        b - the divisor
        Returns:
        the remainder this % b
        Throws:
        java.lang.RuntimeException
        java.lang.ArithmeticException

      • quotient

        public final GF2nPolynomial quotient​(GF2nPolynomial b)
                              throws java.lang.RuntimeException,
                                     java.lang.ArithmeticException
        Divides this by b and stores the quotient in a new PolynomialGF2n.
        Parameters:
        b - the divisor
        Returns:
        the quotient this / b
        Throws:
        java.lang.RuntimeException
        java.lang.ArithmeticException

      • gcd

        public final GF2nPolynomial gcd​(GF2nPolynomial g)
        Computes the greatest common divisor of this and g and returns the result in a new PolynomialGF2n.
        Parameters:
        g - - a GF2nPolynomial
        Returns:
        gcd(this, g)