DES algorithm

Answer the following questions based on the following input to the DES algorithm (assume both plaintext

message and key are the same) Hexademical notation : F E D C B A 0 9 8 7 6 5 4 3 2 1 a. Convert the input

value from hex notation into its equivalent binary notation b. Derive the first round subkey c. Derive the left

and right halves of the plaintext message for use in the first DES round then show how the right half is

expanded to 48-bits d. What is the binary operation used to combine the output from (b) with (c). Show the

output of this operation using your answers from (b) and (c) e. The output from (d) is passed through the

S-box operation. Explain what this operation is for and what is the output using the S-box tables shown in

the lecture slides.

sample Solution