4.18 Using S-DES (see Appendix G on Blackboard), decrypt the
string (10100010) using the key (0111111101) by hand. Show
intermediate results after each function (IP, FK, SW, FK, IP-1).
Then decode the first 4 bits of the plaintext string to a letter
and the second 4 bits to another letter where we encode A through P
in base 2 (i.e., A = 0000, B = 0001, …, P = 1111). Hint: As a
midway check, after the application of SW,...