Security is often one of the most over looked features of an application. This is because it is invisible both to the end user and the developer. The fact that it is invisible does not mean it's unimportant. In fact, if you don't implement proper security it can become the most visible aspect of your site. Imagine having just completed a complex shop application where customers hand over their credit card details online and hackers deface the site. Is that going to help customer confidence?
So, while security is normally invisible to the end user it can also be massively visible and very important. This is why, when developing applications, it is best to spend some time looking at security aspects.
As we go through this chapter, we will look at:
Defining security
Securing the server
Securing Apache
Securing PHP
Securing MySQL
Cryptography
Network security
Secure programming
We will also discuss a few tips and caveats before we sign off with some interesting resources for further reading.