ABSTRACT
In this chapter, the focus is on security and protection issues applicable only in operating systems, deliberately avoiding the broad spectrum of this topic. Protection of a system by using appropriate security measures and mechanisms realized by the built-in protection facilities offered by the OS is the ultimate target that can thwart numerous types of violent attacks launched in the internet age all over the cyber world. The first portion of this chapter deals with the different types of active and passive security attacks attempted on different assets of computer systems and the related design issues of the required security policies and mechanisms. The remaining portions of the chapter describe a spectrum of approaches that provide appropriate protections to the system, including the domain and range of protection. Identification of different types of intruders and different proven methods to prevent them from breaking security is described. Different types of malicious programs (malware), including worms, viruses, flagship security attackers, and their various methods of launching attacks, are briefly narrated. Various types of encryption-decryption-based approaches, including symmetric encryption (private-key encryption) and asymmetric encryption (public-key encryption) schemes, are demonstrated. Last, the different types of protection mechanisms offered by the most popular operating systems, UNIX, Linux, and Windows, to attain each one’s objectives, and subsequently how security systems are built by users on each of these platforms, are narrated as case studies in brief.
