de.flexiprovider.common.util
Class FlexiBigIntUtils

java.lang.Object
  |
  +--de.flexiprovider.common.util.FlexiBigIntUtils

public final class FlexiBigIntUtils

extends java.lang.Object

Method Summary

static boolean	equals(FlexiBigInt[] a, FlexiBigInt[] b) Checks if two FlexiBigInt arrays contain the same entries
static void	fill(FlexiBigInt[] array, FlexiBigInt value) Fill the given FlexiBigInt array with the given value.
static FlexiBigInt[]	subArray(FlexiBigInt[] input, int start, int end) Generates a subarray of a given FlexiBigInt array.
static int[]	toIntArray(FlexiBigInt[] input) Converts a FlexiBigInt array into an integer array
static int[]	toIntArrayModQ(int q, FlexiBigInt[] input) Converts a FlexiBigInt array into an integer array, reducing all FlexiBigInts mod q.
static byte[]	toMinimalByteArray(FlexiBigInt 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(FlexiBigInt[] a,
                             FlexiBigInt[] b)

Checks if two FlexiBigInt arrays contain the same entries

Parameters:

a - first FlexiBigInt array

b - second FlexiBigInt array

Returns:

true or false

fill

public static void fill(FlexiBigInt[] array,
                        FlexiBigInt value)

Fill the given FlexiBigInt array with the given value.

Parameters:

array - the array

value - the value

subArray

public static FlexiBigInt[] subArray(FlexiBigInt[] input,
                                     int start,
                                     int end)

Generates a subarray of a given FlexiBigInt array.

Parameters:

input - - the input FlexiBigInt array

start - - the start index

end - - the end index

Returns:

a subarray of input, ranging from start to end

toIntArray

public static int[] toIntArray(FlexiBigInt[] input)

Converts a FlexiBigInt array into an integer array

Parameters:

input - - the FlexiBigInt array

Returns:

the integer array

toIntArrayModQ

public static int[] toIntArrayModQ(int q,
                                   FlexiBigInt[] input)

Converts a FlexiBigInt array into an integer array, reducing all FlexiBigInts mod q.

Parameters:

q - - the modulus

input - - the FlexiBigInt array

Returns:

the integer array

toMinimalByteArray

public static byte[] toMinimalByteArray(FlexiBigInt value)

Return the value of big as a byte array. Although FlexiBigInt 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 FlexiBigInt value to be converted to a byte array

Returns:

the value big as byte array