Cloud Application Architectures

Privacy Design

In Chapter 5, I talk about all aspects of security and the cloud. As we design your overall application architecture in this chapter, however, it is important to consider how you approach an application architecture for systems that have a special segment of private data, notably e-commerce systems that store credit cards and health care systems with health data. We take a brief look at privacy design here, knowing that a full chapter of security awaits us later.

Privacy in the Cloud

The key to privacy in the cloud—or any other environment—is the strict separation of sensitive data from nonsensitive data followed by the encryption of sensitive elements. The simplest example is storing credit cards. You may have a complex e-commerce application storing many data relationships, but you need to separate out the credit card data from the rest of it to start building a secure e-commerce infrastructure.

Note

When I say you need to separate the data, what I mean is that access to either of the two pieces of your data cannot compromise the privacy of the data. In the case of a credit card, you need to store the credit card number on a different virtual server in a different network segment and encrypt that number. Access to the first set of data provides only customer contact info; access to the credit card number provides only an encrypted credit card number.

Figure 4-5 provides an application architecture in which credit card data can be securely managed.

Figure 4-5. Host credit ...