For starters, the couple could have used stress-tested PGP (Pretty Good Privacy) for point-to-point encrypted email which involves installing a separate piece of client software and the exchanging of public keys.

FORBES: The General, The Biographer, And Unencrypted Email

The U.S. government today announced that it would permit Network Associates Inc. a license allowing it to ship its 128-bit PGP (Pretty Good Privacy) product to a large number of countries, excluding countries such as Iraq and Cuba.

CNN: Zero-Knowledge launches anonymous access

Mr. DEVLIN: Based on the reports I've read about this case, Pellicano is using a system called PGP, which stands for Pretty Good Privacy.

NPR: The Math Behind Pellicano's Code

PGP, an acronym for Pretty Good Privacy, was originally created as a free tool by Philip Zimmermann in the early nineties to allow for private email correspondences and bulletin-board service postings.

FORBES: Symantec Acquires Encryption Provider PGP For $300 Million

More and more, the Bitcoin Project is starting to look like the Pretty Good Privacy (PGP) secure email program with each passing day.

FORBES: As Inflation Rages In Iran, Bitcoin Software Not Available

The company was co-founded by Mike Janke, a former Navy SEAL, and Phil Zimmermann, the creator of Pretty Good Privacy ( PGP) and other Internet encryption for voice and data.

FORBES: Silent Circle Adds Android For Encrypted Voice And Video Calls