////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary> Initializes the permutation network. </summary>
///
/// <remarks>
/// This is where the real work is done. The permutation network is an abstraction of a set of
/// incoming wires and outgoing wires. The permutation is given in terms of those wires, but
/// each indivicual wire represents a particular bit in the input. The bits represented by
/// adjacent wires are separated by a value delta which is equal to 64 / (the size of the
/// permutation). The first wire represents the bit indexed by phase. Thus the bit corresponding
/// to wire i is phase + i * delta. Since size can be calculated by the size of the permutation
/// the only thing we need to make this mapping are the phase and the permutation. Key point is
/// that the permutation references wire numbers running consecutively from 0 to (size - 1), not
/// actual bit positions. Darrellp, 12/7/2011.
/// </remarks>
///
/// <param name="permutation"> The permutation we will use to permute the bits. </param>
/// <param name="phase"> The index of the first bit to be permuted. </param>
////////////////////////////////////////////////////////////////////////////////////////////////////
private void Initialize(byte[] permutation, int phase)
{
PermutationNetwork permutationNetworkEven;
PermutationNetwork permutationNetworkOdd;
int size = permutation.Length;
int delta = 64 / size;
ulong inputMask;
ulong outputMask;
// Get the wiring needed for our two inner networks
byte[][] permutationsInner = GetInnerPermutations(permutation, delta, phase, out inputMask, out outputMask);
// Recursively create those two inner networks
if (size == 4)
{
// The recursion ends here by creating two swappers rather than normal permutation networks
permutationNetworkEven = new Swapper(permutationsInner[0], phase);
permutationNetworkOdd = new Swapper(permutationsInner[1], phase + delta);
}
else
{
// For larger sizes, the inner networks are standard permutation networks
permutationNetworkEven = new PermutationNetwork(permutationsInner[0], phase);
permutationNetworkOdd = new PermutationNetwork(permutationsInner[1], phase + delta);
}
// Extract the masks from our inner permutation networks into our list of masks
ExtractMasks(permutationNetworkEven, permutationNetworkOdd, inputMask, outputMask);
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary> Initializes the permutation network. </summary>
///
/// <remarks>
/// This is where the real work is done. The permutation network is an abstraction of a set of
/// incoming wires and outgoing wires. The permutation is given in terms of those wires, but
/// each indivicual wire represents a particular bit in the input. The bits represented by
/// adjacent wires are separated by a value delta which is equal to 64 / (the size of the
/// permutation). The first wire represents the bit indexed by phase. Thus the bit corresponding
/// to wire i is phase + i * delta. Since size can be calculated by the size of the permutation
/// the only thing we need to make this mapping are the phase and the permutation. Key point is
/// that the permutation references wire numbers running consecutively from 0 to (size - 1), not
/// actual bit positions. Darrellp, 12/7/2011.
/// </remarks>
///
/// <param name="permutation"> The permutation we will use to permute the bits. </param>
/// <param name="phase"> The index of the first bit to be permuted. </param>
////////////////////////////////////////////////////////////////////////////////////////////////////
private void Initialize(byte[] permutation, int phase)
{
PermutationNetwork permutationNetworkEven;
PermutationNetwork permutationNetworkOdd;
int size = permutation.Length;
int delta = 64 / size;
ulong inputMask;
ulong outputMask;
// Get the wiring needed for our two inner networks
byte[][] permutationsInner = GetInnerPermutations(permutation, delta, phase, out inputMask, out outputMask);
// Recursively create those two inner networks
if (size == 4)
{
// The recursion ends here by creating two swappers rather than normal permutation networks
permutationNetworkEven = new Swapper(permutationsInner[0], phase);
permutationNetworkOdd = new Swapper(permutationsInner[1], phase + delta);
}
else
{
// For larger sizes, the inner networks are standard permutation networks
permutationNetworkEven = new PermutationNetwork(permutationsInner[0], phase);
permutationNetworkOdd = new PermutationNetwork(permutationsInner[1], phase + delta);
}
// Extract the masks from our inner permutation networks into our list of masks
ExtractMasks(permutationNetworkEven, permutationNetworkOdd, inputMask, outputMask);
}
