PGP freeware versions should be used for non-commercial purposes only. The following is a list of the most popular freeware PGP versions, past and present.To find out what is the latest version for your platform, click here.
This is an unofficial, "hacked" version of PGP 2.3a, which aimed at correcting the incompatibility problems introduced by MIT PGP 2.6. Please observe that PGP 2.6ui is not a "true" 2.6 version as it is based on the source code for PGP 2.3a, and as such does not include the improvements and bug fixes found in the newer versions. PGP 2.6ui was published by mathew in the UK, but is no longer supported.
Tony Lezard in the UK based this version of PGP on mathew's 2.6ui, but tried to bring it up-to-date with the latest PGP 2.6x improvements (bigger keys, bug-fixes, new command options etc.). PGP 2.62ui can be downloaded from ftp.mantis.co.uk.
This is the most current version of the ui series. It is published by Steve Crompton. It contains fixes and features not available in other versions of PGP. For more information including download locations, see The Unofficial International PGP Home Page
MIT PGP 2.6.2
This is a US-only version of PGP, released and distributed by MIT. It has the following restrictions:
This is a "rebel version" of PGP (the 'g' stands for 'guerilla'). It supports 4096-bit keys, doesn't use RSAREF, and fixes many bugs found in MIT PGP 2.6.2. I don't know much about this version, but you can get it here.
This version of PGP is based on the source code for MIT PGP 2.6.2 and modified for international use. PGP 2.6.3i differs from MIT PGP 2.6.2 in the following ways:
This release fixes a few minor problems in PGP 2.6.3i. Here's the patch.
If you compile the source code for PGP 2.6.3i using the -DUSA option and linking with RSAREF (rsaglue2.c) instead of MPILIB (rsaglue1c.), you will get a version that identifies itself as PGP 2.6.3. It contains all the same bug-fixes and improvements as PGP 2.6.3i, but it will be slightly slower, and the "legal kludge" cannot be disabled. PGP 2.6.3 is not an official PGP version, but is still perfectly legal to use inside the USA. It is only distributed as source code. However, some helpful individuals that have compiled it for their own use, have also made it available to the general public:
PGP 2.6.3in is based on PGP 2.6.3i, but adds many of the features found in PGP 5.0. I don't know much about this version, but you can find it here.
PGP 3.0 is an older name for PGP 5.0. This version took almost three years to complete, and because ViaCrypt had already released PGP version 4.0, the name was changed from 3.0 to 5.0 before release.
PGP 5.0 (formerly known as PGP 3.0) represents a new generation of PGP versions. It adds many new features not found in earlier versions, including support for other encryption algorithms than RSA and IDEA. PGP 5.0 is the first version that is fully integrated with the Windows 95/NT and Macintosh graphical user interfaces.
PGP 5.0i is the latest international version of PGP for MS-DOS, OS/2, Amiga, Atari and Unix. It is basically the same version as PGP 5.0, but because it was compiled from source code that was scanned and OCRed from printed books that were legally exported from the US, it is legal to use in almost any country in the world. You can download PGP 5.0i here.
PGP 5.5i is only available for Windows 95/NT and Macintosh.
This is the latest international PGP version for Windows 95/98/NT and Macintosh.