1. Consider a public key encryption. Ann wants to send Bill a message. Let Annpriv and Annpub be Ann's private and public keys respectively. The same for Bill (Billpriv and Billpub).
(a) If Ann sends a message to Bill, what encryption should Ann use so that only Bill can decrypt the message (secrecy)?
(b) Can Ann encrypt the message so that anyone who receives the message is assured that the message only came from Ann (authenticity)?
(c) Is it possible for Ann to devise a method that will allow for both secrecy and authenticity for her message? Please justify your answer.