Question 3 (total of 6 marks) Choose one of the modes of operation for block ciphers discussed in class. a. Describe in detail how the mode of operation you have chosen works, highlighting features and weaknesses (if any). (2 marks) b. Describe and reference a real-world use of the mode of operation you have chosen, stating and justifying any advantages or disadvantages of this mode of operation in this context. (4 marks) Your answer to part b of Question 3 should not exceed half a page of A4 paper.