Mike Meyers' CompTIA Security+ Certification Guide, Third Edition (Exam SY0-601), 3rd Edition

CHAPTER 2

Cryptography

Now he had learned that a machine, simple in its design, could produce results of infinite complexity.

—Neal Stephenson, Cryptonomicon

Every organization has private data, data accessible by authorized users and not accessible to outsiders. This data includes customer databases; e-mails with critical business strategies; file servers with proprietary recipes and manufacturing processes; cameras sending images of security gates; and Web sites where people type in their names, addresses, and credit card information. Organizations need to keep this data secure. Encryption gives organizations the tools to accomplish this goal.

Encryption is a reversible process of converting data such that to a third party the data is nothing ...