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1. The following key information and right hand side R8 are input into the DES  round function F in the ninth round of the algorithm.  C8 = 11111100 00001111 11000000 1111, D8 = 11111100 00001111 11000000 1111  R8 = 11000110 00110000 00110000 00011100. Use this to calculate K9 and the result of the function F(R8, K9). a. Expand R8 from 32 bits to 48 bits with the Expansion Permutation table We get the new 48 bits string as E(R8) below R8 = 11000110 00110000 00110000 00011100 (32 bits) E(R8) = 01100000 11000001 10100000 00011010 00000000 11111001 (48 bits) b. Calculate C9 and D9 using the table of “Number of Key Bits Shifted per Round” As we know the C8 and D8, then we shift left one place to get C9 and D9 C8  = 11111100 00001111 11000000 1111, D8 = 11111100 00001111 11000000 1111  C9  = 11111000 00011111 10000001 1111, D9 = 11111000 00011111 10000001 1111   c. Calculate K9 using the Permutation table First, C8 + C9 gets the whole 56 bits string then exchange them work out a

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## This note was uploaded on 10/03/2011 for the course SIT 281 taught by Professor Vickymak during the Three '09 term at Deakin.

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