org.spongycastle.pqc.math.linearalgebra

Class BigIntUtils

java.lang.Object

org.spongycastle.pqc.math.linearalgebra.BigIntUtils

public final class BigIntUtils
extends java.lang.Object

FIXME: is this really necessary?!

Method Summary

Modifier and Type	Method and Description
static boolean	equals(java.math.BigInteger[] a, java.math.BigInteger[] b) Checks if two BigInteger arrays contain the same entries
static void	fill(java.math.BigInteger[] array, java.math.BigInteger value) Fill the given BigInteger array with the given value.
static java.math.BigInteger[]	subArray(java.math.BigInteger[] input, int start, int end) Generates a subarray of a given BigInteger array.
static int[]	toIntArray(java.math.BigInteger[] input) Converts a BigInteger array into an integer array
static int[]	toIntArrayModQ(int q, java.math.BigInteger[] input) Converts a BigInteger array into an integer array, reducing all BigIntegers mod q.
static byte[]	toMinimalByteArray(java.math.BigInteger value) Return the value of big as a byte array.

Methods inherited from class java.lang.Object

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

Method Detail

equals

public static boolean equals(java.math.BigInteger[] a,
                             java.math.BigInteger[] b)

Checks if two BigInteger arrays contain the same entries

Parameters:

a - first BigInteger array

b - second BigInteger array

Returns:

true or false

fill

public static void fill(java.math.BigInteger[] array,
                        java.math.BigInteger value)

Fill the given BigInteger array with the given value.

Parameters:

array - the array

value - the value

subArray

public static java.math.BigInteger[] subArray(java.math.BigInteger[] input,
                                              int start,
                                              int end)

Generates a subarray of a given BigInteger array.

Parameters:

input - - the input BigInteger array

start - - the start index

end - - the end index

Returns:

a subarray of input, ranging from start to end

toIntArray

public static int[] toIntArray(java.math.BigInteger[] input)

Converts a BigInteger array into an integer array

Parameters:

input - - the BigInteger array

Returns:

the integer array

toIntArrayModQ

public static int[] toIntArrayModQ(int q,
                                   java.math.BigInteger[] input)

Converts a BigInteger array into an integer array, reducing all BigIntegers mod q.

Parameters:

q - - the modulus

input - - the BigInteger array

Returns:

the integer array

toMinimalByteArray

public static byte[] toMinimalByteArray(java.math.BigInteger value)

Return the value of big as a byte array. Although BigInteger has such a method, it uses an extra bit to indicate the sign of the number. For elliptic curve cryptography, the numbers usually are positive. Thus, this helper method returns a byte array of minimal length, ignoring the sign of the number.

Parameters:

value - the BigInteger value to be converted to a byte array

Returns:

the value big as byte array