Expand the key 1010 0001 1111 0101 using Simplified AES. As a check, the last four bits of key for round 2 should be 0011 (that is k28k29k30k31). In Simplified AES, for function MC we showed an easier approach by showing what each column is transformed to, using only XOR of bits (shown in page 21 of lecture notes). We know that MC-1 is multiplying by c(z)-1 = xz + (x3 + 1) in F16/21/(22 + 1). It would be nicer to have this in a similar form as the table for MC. So multiply (box3 + b1 x2 + b2x +63)2 + (64x3 + b5x2 +b6x+b7) with xz + (x3 +1) in F16[2]/(22 +1) by hand to show what of bob1b2b3 6465beb goes to. Use the expanded key from question 2 and find c(z)-2K1 (that's the same as MC-4(K)). Decrypt the string 1100 0001 0001 0011 with the key 1010 0001 1111 0101 using Simplified AES. Note that this is the same key as in question 2, so you already have the expanded key. Use AK, O SR-1 o NS-1 o Ac(z)-1K, O MC-1 0 SR-1 o NS-1 0 AKz. (Remember that means Ak, is the first step.) Then decode to a pair of ASCII characters. Please write your answer neatly and write down which step you're doing. As a midway check: After MC-1, you should have 1010 1100 0010 1011