= 0 =

Compute the following AES operations: (a) The initial AES AddRoundKey layer. (6 pts) (b) The SubBytes layer from the first round. (6 pts) (c) The ShiftRows layer from the first round. (6 pts) (d) The MixColumn layer from the first round applied only to the to the first column of the internal state. (10 pts)

Now, let plaintext be from problem 1 with the first byte changed to ff. That is,

=

Answer the following questions. (a) Compute the results of the initial AddRoundKey layer with as the input. How many bytes are different from your answer to problem 1(a)? (4 pts) (b) Compute the results of the round 1 SubBytes layer with the results from part (a) as the input. How many bytes are different from your answer to problem 1(b)? (4 pts) (c) Compute the results of the round 1 ShiftRows layer with the results from part (b) as the input. How many bytes are different from your answer to problem 1(c)? (4 pts) (d) Compute the results of the round 1 MixColumn layer on the first column of the results from part (c) as the input. How many bytes are different from your answer to problem 1(d)? (4 pts) (e) How many bytes would be different in the remaining 3 columns if were used instead of ? (2 pts) (f) How many bytes would be different at the end of round 1 if were used instead of ? (2 pts) (g) How many bytes would be different at the end of round 2 if were used instead of ? (2 pts)