During the 1990s, Phil was the target of a three-year criminal investigation because the US Federal Government held that export restrictions for cryptographic software were violated when his invention, Pretty Good Privacy (PGP), spread all around the world following its publication as freeware. Despite a lack of funding, a staff, or even a company to stand behind him, and despite government persecution, PGP nonetheless, became the most widely used e-mail encryption software in the world.

After the government dropped its case in early 1996, Phil founded PGP Inc., which was acquired the following year by Network Associates where Phil stayed on for three years as a senior fellow. In August 2002, PGP was acquired from Network Associates by a new company called PGP Corporation where Phil now serves as a special advisor and consultant. Phil is also consulting for a number of companies and industry organizations on cryptographic matters and is also a fellow at the Stanford Law School Center for Internet and Society.

In this interview with IT Conversations' host Doug Kaye, Phil explains how reading a kids' book on secret codes and invisible ink led to a career in cryptography. He explains why he developed PGP and how he obtained a license to use the Diffie-Hellman algorithm even though it was held by a patent cartel at the time.

Phil also talks about the history and future of PGP, tells the odd-bedfellows story of finding himself in agreement with Attorney General John Ashcroft on issues of encryption exports, the solutions to spam, and why he rarely digitally signs his own email messages.