Q5: We know a message authentication code (MAC) is for the purpose of ensuring data integrity. (5 points each) 1. Checksum adds all the bits of the message (or blocks), is checksum a good way to construct an MAC scheme? How about a hash function? h(m), and m, o will be sent along. 2. If we use a hash to generate a tag as follows: o = hk) om Would this be a secure MAC? briefly explain