Can I use PGP under a “swapping” operating system like Windows, OS/2 or UNIX?
Yes. PGP 2.x runs OK in most “DOS windows” for these systems, and PGP can be built natively for many of them as well. The problem with using PGP on a system that swaps is that the system will often swap PGP out to disk while it is processing your pass phrase. If this happens at the right time, your pass phrase could end up in cleartext in your swap file. How easy it is to swap “at the right time” depends on the operating system; Windows reportedly swaps the pass phrase to disk quite regularly, though it is also one of the most inefficient systems. PGP does make every attempt to not keep the pass phrase in memory by “wiping” memory used to hold the pass phrase before freeing it, but this solution isn’t perfect. Because swapfiles shrink, and many applications (e.g. Microsoft Word and Microsoft compilers) grab disk space (and unused memory) and don’t always fill it all out, you will regularly get fragments of other work embedded in files unrelated to it. Disabling swapping (after getting
