Imagine you’re at a border crossing, and the guard asks you to hand over all of your electronics for screening. The guard then asks that you unlock your device, provide passwords and decryption keys. Right now, he’s asking nicely, but he happens to be carrying an unpleasant-looking rubber hose, Yes, cryptographers actually do call this “rubber hose cryptanalysis.” and appears to be willing to use it. Now imagine you’re a journalist covering war crimes in the country you’re trying to leave. So, what can you do?

PGP stands for Pretty Good Privacy. At it’s core, it is an internet standard (called OpenPGP) used for data encryption and digital signatures. Software that employs this standard is available in both a free, open source version produced by the Free Software Foundation called the GNU Privacy Guard (or GPG for short) as well as a low-cost commercial version.