To encrypt the message 65 using Alice's public RSA key of N=10403 and e=13, compute 65^13 mod 10403. To calculate the decryption key, find the integer d such that ed=1 mod φ(N), where φ(N)=(N-1)(N-2)...(N-p+1)(N-q+1) and N=pq for prime numbers p and q.