Integrated Security Technologies and Solutions - Volume II: Cisco Security Solutions for Network Access Control, Segmentation, Context Sharing, Secure Connectivity and Virtualization, First Edition

Chapter 8. Security Connectivity

Cryptography is nothing new. One of the earliest forms of cryptography was found to be used in the ancient writings of hieroglyphics in Egypt around 1900 BCE. At the basic level, cryptography is the use of codes and ciphers to hide the plaintext of a message in a manner that it can be deciphered only with the use of a key. Cryptography can be as rudimentary as a scytale, a strip of leather or paper wrapped around a pole and engraved with the message. When the strip is straight, the message is obfuscated from anyone who sees it in its travels to the intended recipient and can be decrypted only with the key, which in this case is the carrier of the message knowing the diameter of the pole around which to rewrap ...