Pretty Good Privacy (PGP)
A system of encryption designed by Phil Zimmerman that is widely used and distributed on the Internet. PGP uses a public key that can be freely disseminated and used by anyone to encode a message and a private key that is kept only by the intended recipient of the encoded messages. The private key is used by the recipient to decode messages encrypted using the public key. Converting the public key into a private key requires factoring large numbers. If the number of bits in the public key is large enough, then the factors cannot be computed in a reasonable amount of time using conventional computation (and thus the encoded information remains secure). Quantum computing (with a sufficient number of qu-bits) would destroy this type of encryption.
Articles on KurzweilAI.net that refer to Pretty Good Privacy (PGP)The Age of Spiritual Machines: Glossary By Ray Kurzweil
News Articles that refer to Pretty Good Privacy (PGP)The Personal Genome Project Has a Growth Spurt
MIT Pretty Good Privacy Distribution Center