Security+ Question of the Week: Digital Envelope

The correct answer is A.

A digital envelope is created using the recipient’s public key, so the recipient’s private key is used to open it. The sender’s public key can be used to create a digital envelope that the sender will open in the future, thus the sender’s public key and the recipient’s public key are the same thing in this situation. A previous symmetric key is typically not used for any purpose, in fact it should not be retained after use. The session key is a symmetric key, but it would be the content of the envelope, rather than the key used to open the envelope.