Practical Security

Here be dragons.

Anon.

Chapter 3Cryptography

Cryptography is the sexiest topic in computer security. The word conjures up images of spies, adventures, and eccentric math geniuses. Move past the Hollywood take on cryptography, and you’ll find that it really is a fascinating field. It ties together math, logic, low-level bit flipping, and even hardware design.

We aren’t going to cover any of that.

Most coverage of cryptography starts with a discussion of prime numbers and the complexity of factoring composite numbers. This is done with an eye toward guiding you through implementing RSA encryption. This chapter will instead attempt to dissuade you from ever implementing any cryptography whatsoever. We’ll see by example that implementing cryptography ...