Network Security: [5 marks] Imagine that you are developing a messenger app (like WhatApp). It lets users make calls over the Internet. Your requirements are: (i) encrypt data communication for each call. (ii) use a unique encryption key for each couple of users but (iii) prevent this key from getting shared over the Internet. (a) How can you achieve this? [2] (b) Briefly outline the algorithm. [3] Please ans by 15 minute. Very Urgent.