Lo = Ro What is the result of applying the expansion box to R,? E(Ro) = What is the result of XORing the subkey with E(Ro)? ko O E(Ro) = We now apply the S-box transformation. S(ko Ð E(Ro)) = Finally...

Extracted text: Lo = Ro What is the result of applying the expansion box to R,? E(Ro) = What is the result of XORing the subkey with E(Ro)? ko O E(Ro) = We now apply the S-box transformation. S(ko Ð E(Ro)) = Finally we apply the permutation box to complete the function f. f(Ro) = P(S(ko Ð E(Ro))) = We can now compute the state of DES going into the next round. L = R1 =


Extracted text: Chapter 3: Problem 4 Previous Problem Problem List Next Problem -In this problem we will work through a round of DES. For notational simplicity, assume it is the first round. Please enter all answers as strings of 0's and 1's. The input is the 64 bit block 0000000000000000000000000100000000001000000001000000000100000001 Suppose that the subkey for the current round is this 48 bit number: 000000000000000000000000000000000000000000100000 What does the 64 bit state look like after the IP transformation is applied to the input? Now find Lo and Ro, the left and right halves of the state. Lo = Ro = What is the result of applying the expansion box to Ro? E(Ro) =