Editing Pretty Good Privacy (section)

===PGP 3 and founding of PGP Inc.===
During this turmoil, Zimmermann's team worked on a new version of PGP encryption called PGP 3. This new version was to have considerable security improvements, including a new certificate structure that fixed small security flaws in the PGP 2.x certificates as well as permitting a certificate to include separate keys for signing and encryption. Furthermore, the experience with patent and export problems led them to eschew patents entirely. PGP 3 introduced the use of the [[CAST-128]] (a.k.a. CAST5) symmetric key algorithm, and the [[Digital Signature Algorithm|DSA]] and [[ElGamal]] asymmetric key algorithms, all of which were unencumbered by patents.

{{anchor|PGP_Inc}}After the Federal criminal investigation ended in 1996, Zimmermann and his team started a company to produce new versions of PGP encryption. They merged with Viacrypt (to whom Zimmermann had sold commercial rights and who had [[licensed]] RSA directly from [[RSADSI]]), which then changed its name to PGP Incorporated. The newly combined Viacrypt/PGP team started work on new versions of PGP encryption based on the PGP 3 system. Unlike PGP 2, which was an exclusively [[command line]] program, PGP 3 was designed from the start as a [[software library]] allowing users to work from a command line or inside a [[GUI]] environment. The original agreement between Viacrypt and the Zimmermann team had been that Viacrypt would have even-numbered versions and Zimmermann odd-numbered versions. Viacrypt, thus, created a new version (based on PGP 2) that they called PGP 4. To remove confusion about how it could be that PGP 3 was the successor to PGP 4, PGP 3 was renamed and released as PGP 5 in May 1997.