unsafe void k1()
        {
            int length = 0, BLOCK_SIZE = 0;
            byte[] sarray = new byte[length];
            byte[] darray = new byte[length];
            uint* prev = null;

            fixed (byte* b1 = sarray)
            fixed (byte* b2=darray)
            {
                byte* src = b1;
                byte* dest = b2;
                for (int i = 0; i < length; i += BLOCK_SIZE)
                {
                    if (prev == null)
                    {
                        *(uint*)(dest + i) = *(uint*)(src + i) ^ (*prev);
                    }
                    else
                    {
                        *(uint*)(dest + i) = *(uint*)(src + i);
                    }
                    prev = (uint*)(src + i);
                }
            }

        }