Initial Permutation "o lp( m) 070 Initial permutation 585042342618102 605244362820124 625446383022146 645648403224168 57494133251791 595143352719113 615345372921135 635547393123157
11 • x0 = IP(m) = L0R0 Initial Permutation 58 50 42 34 26 18 10 2 60 52 44 36 28 20 12 4 62 54 46 38 30 22 14 6 64 56 48 40 32 24 16 8 57 49 41 33 25 17 9 1 59 51 43 35 27 19 11 3 61 53 45 37 29 21 13 5 63 55 47 39 31 23 15 7 Initial Permutation
Rounds of confusion and Diffusion Plaintext Block(64 bits) Key(64 bits) Initial Permutation Strip Parity(56 bits) Round 1 Round 2 Round 16 Reverse Permutation Ciphertext Block(64 bits)k 12
12 Rounds of Confusion and Diffusion Initial Permutation Strip Parity (56 bits) Key (64 bits) Round 1 Round 2 Round 16 Reverse Permutation Plaintext Block (64 bits) Ciphertext Block (64 bits)
Input Initial permutation R K R R Irregular swap R inverse permutation output CtC·· 13
13
One round of des i-1 R 1 Keyi-1 32 32 Shift Shift 56 Expansion Permutation Compression Permutation 48 Feistel 48 Network S-Box Substitution 32 P-Box Permutation 32 32 56 e 14
14 One Round of DES Expansion Permutation 48 P-Box Permutation S-Box Substitution 32 Shift Shift 48 Compression Permutation Feistel Network 56 32 32 Li-1 Ri-1 Keyi-1 Li Ri Keyi 32 32 56
Round function The round function is g([L:1R1:1],K1)=(L1R Where Li=R andr; =lilo(R- 1, Ki) 15
15 Round function The round function is: g([Li-1 ,Ri-1 ]),Ki ) = (Li ,Ri ), where Li = Ri-1 and Ri = Li-1 f (Ri-1 , Ki )