Linux® Desk Reference, Second Edition

Introduction

Cryptography, which literally means “secret writing,” is the process of turning a string of plain text into something that looks like chicken scratches, and is more or less thoroughly unreadable (encrypting), and optionally, turning it back into legible text again (decrypting).

Until the early 1990s there was virtually no information publicly available on cryptography. I know, because I looked. With the advent of the Internet and the obvious need for good data security, this is no longer the case, and there are some excellent books and software easily available. The U.S. government is still somewhat grumpy about this, however. The PGP software discussed in this section is not part of a common Linux release. It is, in fact, illegal ...