Question 8 2.5 pts Consider the two S-boxes S1 and S2 of DES shown. Three he dig

Question

Question 8 2.5 pts Consider the two S-boxes S1 and S2 of DES shown. Three he digits 12 bit are provided to these two S boxes The ig her oder si bits are ed to st and the love order s, , are fed to S2 For the six bits input to S1, the first and last bits are used to select the row and the middle four bits are used to select the coun n·Note that each S bo as our ows numbered 0,1.2, and 3 and sixteen columns numbered O to 15. So, two bits are sufficient to select a row, as 22 -4 and four bits are sufficient to select a column, as 2 16. The output from each S box is a four bit binary number, which means that the output from each S box ranges from 0 to 15. 1 CO C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 RO 15 12 8 2 4 917 511 3 14 10 0 613 R1 14 4 13 1 2 15 11 8 3 10 6 12 5907 R2 015 7 4 14 213 1 10 6 12 1195 38 R3|4| 1|14| 8|1316|2|11|15|12| 9 | 7 | 3 | 10| 5 | O S2 COC1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 RO 13 8 10 1 3 15 4 2 11 6 7 12 05 149 R115 1814 6 11 3 4 97 2 13 120510 R2 0 147 1110 4 13 15 812 69 3 2 15 R3 3 13 47 15 2 8 14 12 0 1 10 6 9 11 5 Given the 12 bit hex input of F3416 calculate the S1 & S2 outputs. Express your answer in hexadecimal. o C3 03C o 7C o 73

Explanation / Answer

Answer: 3C


Explanation

F34 in Binary is 1111 0011 0100

Divided in 6 bits each are 111100 and 110100

Lets consider . ===> 111100
=> 1 is first bot and 0 is last bit -> 10 means R2 is the row
Middle 4 bit = 1110 is the column = C14

See the Table R2 C14 Value is 3

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Lets consider . ===> 110100
=> 1 is first bit and 0 is last bit -> 10 means R2 is the row
Middle 4 bit = 1010 is the column = C10

See the Table R2 C10 Value is C

Hence 3C is the answer

PLEASE UPVOTE if helpful

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