Editing Internet security (section)

==== Pretty Good Privacy (PGP) ====
{{Main|Pretty Good Privacy}}

[[Pretty Good Privacy]] provides confidentiality by encrypting messages to be transmitted or data files to be stored using an encryption algorithm such as [[Triple DES]] or [[CAST-128]]. Email messages can be protected by using cryptography in various ways, such as the following:
*[[Digital signature|Digitally signing]] the message to ensure its integrity and confirm the sender's identity.
*Encrypting the message body of an email message to ensure its confidentiality.
*Encrypting the communications between mail servers to protect the confidentiality of both message body and message header.

The first two methods, message signing and message body encryption, are often used together; however, encrypting the transmissions between mail servers is typically used only when two organizations want to protect emails regularly sent between them. For example, the organizations could establish a [[virtual private network]] (VPN) to encrypt communications between their mail servers.<ref>{{cite web|url=http://itcd.hq.nasa.gov/networking-vpn.html|title=Virtual Private Network|publisher=NASA|access-date=2014-02-14|archive-url=https://web.archive.org/web/20130603122059/http://itcd.hq.nasa.gov/networking-vpn.html|archive-date=2013-06-03}}</ref> Unlike methods that only encrypt a message body, a VPN can encrypt all communication over the connection, including email header information such as senders, recipients, and subjects. However, a VPN does not provide a message signing mechanism, nor can it provide protection for email messages along the entire route from sender to recipient.