The story of PGP and GPG
Webmonkey has published 
the introductory chapter to PGP & GPG: Email for the Practical Paranoid by Michael W. Lucas.
It covers Phil Zimmermann’s first steps with PGP, the lawsuits with the US Government, the launch of OpenPGP, GnuPG, legal aspects of encryption and more.
A brief quotation:
The ideas behind PGP had been known and understood by computer scientists and mathematicians for years, so the underlying concepts weren’t truly innovative. Zimmermann’s real innovation was in making these tools usable by anyone with a home computer. Even early versions of PGP gave people with standard DOS-based home computers access to military-grade encryption.
UPDATE: Mirko posts a link in the comments to an audio interview with Jon Callas , CTO at PGP Corporation, who also explains the history of PGP. Thanks.
Related posts
April 28th, 2006 at 4:55 am
You should take a look at “The Story of PGP” we made at HNS with Jon Callas, the founder of PGP Corporation and hear it in his own words:
http://www.net-security.org/article.php?id=870