Operating Systems: Concurrent and Distributed Software Design

2.9. Security and protection

The topic of security is huge and includes all aspects of controlling access to computers, networks and the information stored, processed and transferred in computer systems (Anderson, 2001; Schneier, 1996). In outline, security comprises:

• External controls –security classifications

  A general framework for classifying computer systems is given in the above references. A framework may relate only to internal mechanisms or may cover the classification of information into 'top secret', 'secret', etc. The people using the computer system are then tagged according to which categories of information they may read, write and transfer. The system must be able to enforce such specified policies.

• Encryption

  The idea of encryption ...