Inside des Xo=P(m)= 07v0 16 Rounds,=1,2,,16: =L40f -1 Where f(Ri, Ki=p(s(e(rio ki), with operations E(expansion S(S-box lookup), and P some (permutation) c=|P1(L16R16) 1010 Inside DES • x0 = IP(m) = L0R0 . • 16 Rounds, i = 1, 2, …, 16: Li := Ri-1 , Ri := Li-1  f (Ri-1 , Ki ), where f (Ri-1 , Ki ) = P(S(E(Ri-1 )  Ki )), with operations E (expansion), S (S-box lookup), and P some (permutation). • c = IP-1 (L16R16)