SUSE LINUX Enterprise Server 9 Administrator's Handbook

Chapter 11 Network Security Concepts

Today, information comes in many forms, and consequently, methods of securing it vary. Instead of dividing information into categories based on content, threat analysis and its protection should be based on methods of processing and storage. These methods can be divided into three general categories:

Physical—Traditionally, information is “physically recorded” (say, in the form of ink-and-paper or electronically in bits-and-bytes) and stored somewhere (for example, in a box, safe, diskette, or hard drive). Therefore, classical security generally focuses on physical protection, such as access control to buildings, ...