Editing Pretty Good Privacy (section)

===Confidentiality===
PGP can be used to send messages confidentially.<ref>{{Cite IETF|rfc=1991|last3=Zimmermann|first3=P.|last1=Atkins|first1=D.|last2=Stallings|first2=W.|date=August 1996|title=PGP Message Exchange Formats}}</ref> For this, PGP uses a [[hybrid cryptosystem]] by combining [[Symmetric key encryption|symmetric-key encryption]] and public-key encryption. The message is encrypted using a symmetric encryption algorithm, which requires a [[Symmetric-key algorithm|symmetric key]] generated by the sender. The symmetric key is used only once and is also called a [[session key]]. The message and its session key are sent to the receiver. The session key must be sent to the receiver so they know how to decrypt the message, but to protect it during transmission it is encrypted with the receiver's public key. Only the private key belonging to the receiver can decrypt the session key, and use it to symmetrically decrypt the message.