private UInt64 DecodeBlock(UInt64 block)
{
UInt32 b = block.HiWord();
UInt32 a = block.LoWord();
for (int i = 0; i < RoundsCount; i++)
{
var temp = a;
a = b ^ FeistelFunc(a, _roundKeys[i]);
b = temp;
}
UInt64 encodedBlock = a.Combine(b);
return encodedBlock;
}
