Security for Web Developers

Chapter 5. Building Reliable Code

You might wonder why this book contains a chapter about building reliable code when the topic is security. An interrelation exists between application speed, reliability, and security. Each of these elements has a role to play in turning a good application into a great application. You can’t emphasize one over the other without diminishing your application in some way. Of course, companies do make the conscious decision to emphasize one element over another, but usually to gain specific goals. For example, you may have a legal requirement to protect applications at all costs, in which case you probably need to sacrifice some speed and reliability to achieve the goal. However, for most applications, the balance between the three elements is critical. Until you understand the interactions between speed, reliability, and security, it’s nearly impossible to achieve an application with the maximum possible security in place, and it is impossible to create an application that performs well in an environment where all three elements are prized.

This chapter views reliability as it relates to security. In other words, it examines how you balance reliability in order to achieve specific security goals in your organization. It also considers reliability as a statistical science, although the chapter won’t bore you with the specifics of reliability calculations. The point is to understand the concept of calculated risk with regard to the state of security ...