Cryptography, Security, Math, Encryption, Data Security.
first prove that φ(n) = (p-1)*(q-1). When n is a prime number, every number less than n is relatively prime to n, so φ(n) equals n-1 for a prime number n. We are working with n = p*q, where p and q are distinct prime numbers. The numbers that are not relatively prime to n are precisely the