PHP & MySQL® Web Development All-in-One Desk Reference for Dummies®

Chapter 2. An Overview of Authentication and Encryption

In This Chapter

• Authenticating users in a number of ways

• Using encryption to keep data secure

This chapter gets into some pretty heavy stuff, but don't worry — you don't need a PhD in mathematics to lock up your application. As long as you can effectively authenticate users and encrypt sensitive data, you'll have a good head start on a secure application.

In this chapter, we start out with authentication methods and show you some methods that are being used every day to make sure people who should have access to information get it, and everyone else is locked out. You can choose which authentication methods make sense for your application.

The second half of this chapter is all about encrypting data. We don't get into the math involved in the leading encryption algorithms — if you're in a position where you need to know how those algorithms work, chances are you already know most of what's covered here. Instead, we stick to how those algorithms work in real life to keep prying eyes out of sensitive data.

There's a lot going on in this chapter, so let's get to it.