3. Why is the middle portion of 3DES a decryption rather than an encryption? 4. This problem provides a numerical example of initialization of array S for 0011001100110011 with keylen-16 RC4. We start with the key K a) Derive array T after the initialization. You can just list the first 16 elements of T for i = 0 to 255 do b) Calculate the first 8 elements of array S after the following initial permutation of S for i - 0 to 255 do Swap (S [il, s[j]); 5. What RC4 key value wll leave S unchanged during initialization? That is, after the initial permutation of S, the entries of S will be equal to the values from 0 through 255 in ascending order