Network security basics

Writing a basic article on network security is something like writing a brief introduction to flying a commercial airliner. Much must be omitted, and an optimistic goal is to enable the reader to appreciate the skills required. The first question to address is what we mean by "network security." Several possible fields of endeavor come to mind within this broad topic, and each is worthy of a lengthy article. To begin, virtually all the security policy issues apply to network as well as general computer security considerations. In fact, viewed from this perspective, network security is a subset of computer security. The art and science of cryptography and its role in providing confidentiality, integrity, and authentication represents another distinct focus even though it\´s an integral feature of network security policy. The topic also includes design and configuration issues for both network-perimeter and computer system security. The practical networking aspects of security include computer intrusion detection, traffic analysis, and network monitoring. This article focuses on these aspects because they principally entail a networking perspective.