a friendly introduction to number theory 3rd edition에 121쪽에
exercise 18.2번 문제입니다. ㅜㅜ
도저히 문제가 뭘 하라는 건지 모르겠어서...........
18.2 It may appear that RSA decryption does not work if you are unlucky enough to choose a message a that is not relatively prime to m. of course, if m=pq and p and q are large, that is very unlikely to occur.
(a) Show that in fact RSA decryption ddoes work for all messages a, regardless of wheter or not they have a factor in common with m
(b) More generally, show that RSA decryption works for all messages a as long as m is a product of distinct primes.
(c) Give an example with m=18 and a=3 where RSA decryption does not work. [Remember, k must be c hosen relatively prime to Ø(m)=6