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?

2. If we use one time pad to generate a tag, i.e., = k m, and m, will be sent along. Would this be a secure MAC? briefly explain.