30-09-2009, 07:08 AM
Pretty Good Privacy (PGP) is computer program that provides cryptographic privacy and authentication. PGP is often used for signing, encrypting and decrypting e-mails to increase the security of e-mail communications , is a public key encryption program originally written by Phil Zimmermann in . Over the past few years, PGP has got thousands of adherent supporters all over the globe and has become a de-facto standard for encryption of email on the Internet
PGP encryption uses a serial combination of hashing, compression, symmetric key cryptography, finally, public-key cryptography; each step uses one of several supported algorithms. Each public key is bound to a user name and/or an e-mail address. The first version of this system was generally known as a web of trust to contrast with the X.509 system which uses hierarchical approach based on certificate authority and which was added to PGP implementations later. Current versions of PGP encryption include both options through an automated key management server
