Cryptography(repost)

Hi, There is a sentence at the beginning of the document. It says "Find the solutions of following questions(or solve them, it is up to you). Then prepare a report thatcompares this solutions with the solutions of your real homework." I'll make the second part. I need your help for only the first part. So, I need the solutions of the questions. It says "Find the solutions of following questions" but I could not find them with an internet search.