Grade the information held by the system for sensitivity. Encrypt the most sensitive items of data using encryption and obfuscation techniques. All public data, such as catalog information held in caches and in memory on the web servers is held in plain text. However, credit card details are held in encrypted form. The only place in the system that such details appear in plain text is in memory on the application server as it is delivering this information, for example, the credit card processing agency.

This pattern mainly applies to software, although hardware acceleration may be used.