This problem treats the RSA public key cryptosystem. 1. Can a user of RSA choose the encryption…

This problem treats the RSA public key cryptosystem. 1. Can a user of RSA choose the encryption exponent e to be even, e.g. e = 4. Solution No, since then gcd(e, f(N)) 6= 1 as 2|f(N) = (p – 1)(q – 1). 23 2. Let e and e 0 be two different public keys such that e 0 is derived from e by flipping one zero to one (0 ? 1) in the binary representation of e. Show that gcd(e, e0 ) = 1. Hint: Compare the divisors of e and e 0 .