Communication networks are used to transfer valuable and confidential information for a variety of purposes. As a consequence, they attract the attention of people who intend to steal or misuse information, or to disrupt or destroy the systems storing or communicating it. In this unit you will study some of the main issues involved in achieving a reasonable degree of resilience against network attacks. Some attacks are planned and specifically targeted, whereas others may be opportunistic, resulting from eavesdropping activities.
Threats to network security are continually changing as vulnerabilities in both established and newly introduced systems are discovered, and solutions to counter those threats are needed. Studying this unit should give you an insight into the more enduring principles of network security rather than detailed accounts of current solutions.
The aims of this unit are to describe some factors that affect the security of networks and data communications, and their implications for users; and to introduce some basic types of security service and their components, and indicate how these are applied in networks.