Question

On perform the Mix Columns transformation for the sequence of bytes “77 89 AB CD” we get output

(a) {01 55 EE 4A}

(b) {0A 44 EF 4A}

(c) {08 55 FF 3A}

(d) {09 44 DD 4A}

This question was addressed to me in a job interview.

My question comes from The AES Algorthm in division Advanced Encryption Algorithm and Block Cipher Operation of Cryptograph & Network Security

Answer 1

Right answer is (c) {08 55 FF 3A}

To explain I would say: Perform the mix columns transformation to obtain the output {08 55 FF 3A}.