In an open network such as the Internet, message privacy, particularly for e-commerce transactions, requires encryption. The most common approach on the Web is through a public key infrastructure (PKI). For e-mail, many people use Pretty Good Privacy (PGP), which lets an individual encrypt a message or simply send a digital signature that can be used to verify that the message was not tampered with enroute. RELATED TERM. Pretty Good Privacy ID; Pretty Good Privacy fingerprint
