Cryptography Basics

An essential component of IT security involves the use of cryptography. In this chapter we will look at the basics of cryptography and provide an overview of a number of different types of cryptography.

What is Cryptography?

Cryptography describes a process of encrypting information so that its meaning is hidden from those who do not know how to decrypt the information. The concept of cryptography began around the same time that humans learned to communicate language through the written word. Over time many different approaches to cryptography have been used ranging from basic shifting of alphabetical letters to complex mechanical and electronic encryption methods.

It is impossible to overemphasize the importance of cryptography, both in the past and in the context of today's high tech world. The ability to break the encryption used by opposing sides in wars has shifted the balance of power in the world, and without cryptography in computing it would be impossible to perform tasks we take for granted such as securely purchase items on the internet or remotely log into servers from outside a company firewall. Even credit cards would not exist if there was no way to encrypt the data stored on the magnetic strips.