SULIT (EKT 355) Question6 Soalan 6 (C4, C6, C03, C04. P02, P03 and P05) (a) Consider the block cipher in figure 4. Suppose that each block cipher Ti simply reverses the order of the eight input bits (so that, for example, 110000 become 00001111) Further suppose that the 64-bit scrambler does not modify any bits (so that the output value of the mth bit is equal to the input value of the mth bit) Pertimbangon hlok cipher' dalam Gambarajah 4. Diandaikan setiap chipher' blok Ti menterbalikkan sususan lopan musukan bit (jadi sebagai contoh 11110000 menjadi 00001111), Seterusnya, andaikan rang 64 bit 'serumbler tidak mengubah sebarang bit (jadi nilai keluaran ke-m bit adalah sama dengan nilai masukan ke-m bi) (i) Observe the value of the output when n-3 and the original 64-bit input equal to 10100000 repeated eight times. Gambarkun nilai keluaran apabila n-3 dan original 64-bit masukan sama dengan 10100000 diulang lupuan kali (ii) Repeat (i) when the last bit of the original 64-bit input changes from 0 to 1 Ulang ti upabila bit terakhir bagi masukan original 64-bit dari 0 to 1) (iii)Assuming that the 64-bit scrambler inverses the order of the 64 bits. Observe the value of the output when n=3 and the original 64-bit input equals to 10100000 [Andaikun yung 64-bit scrambler' menterbalikkan susunan bagi 64 bits. Gambarkan nilai keluaran upuhila n 3 and masukan original 64-bit sama dengan 10100000) (12 Marks/Markah) 64-bit input 8 bits 8 bits8bits 8 bits bits 8 bits 8 bits 8 bits Ts Loop for n rounds 8 bits 8 bits 8bits8 bits 8 bits 8 bits8 bits 8 bits 64-bit scrambler 64-bit output Figure 4. [Rajah 4 SULIT