Judy, the high-class reporter for foreign affairs learned about asymmetric cryptography, and proposed to the security team at the paper to generate for her a pair of public/private RSA keys, to allow her to publish the public key, and encourage citizens in oppressed regimes to prepare to her using that public key, and to assure the preparers that only she could decrypt their messages, and therefore they have nothing to fear from the regime they live under. Tim, on the security team said: "You would put your informers in danger. The regime will detect the ciphertext and coerce the preparer to disclose its content. " "Not really," answered Judy: "the informer could use a different key, that would decrypt the ciphertext to an innocuous plaintext". Then Rachel, the security chief, said: "What if a hacker from the oppressive regime will pretend to be you, and publish his key as being yours -- and so attract and trap dissidents?" "This won't work" answered Judy. People using the fake public key will see a mismatch on the Euler function". "I am sorry" burst in Jerry, but "I prefer Diffie Hellman" for the purpose of facilitating a back and forth communication channel". "That won't be a good idea because with Diffie-Hellman I won't know for sure that I am not talking to a secret agent from the regime, but with RSA I the identity of the other party is firmly established". 

The group eventually realizes that you just graduated from cryptography class, so they come to you to resolve the issues between: Tim and Judy, Rachel and Judy, and Jerry and Judy. You say?