Operating Systems

I. Introduction to Protecting Operating Systems

According to Robert N.M. Watson, in his April 2012 dissertation, “New approaches to operating system security extensibility”, the underpinnings of modern day operating systems (OS) owe a great deal of their history to time sharing systems of the 1960s and 1970s. In 1975, Saltzer and Schroeder published a work on the principles of securing information within operating systems and this work has withstood technological advances and the passage of time quite well (p. 163). Computing concepts such as system hardware abstraction, process separation application models, common function libraries, user interaction management, storage and communication services, and resource management, all can be traced back to these older systems (p. 15). Since the burgeoning home computer market in the 1980s and the advent of the modern Internet in the 1990s, computer operating systems have now opened up communication to all corners of the globe, making information readily available to anyone connected to the Web, while also providing new avenues of attack for those who are not securing their computer systems. Due to this new level of interconnectivity of operating systems, the need for security has grown exponentially. Now many computer systems have common security features due to the growth of networked systems. Security features can include cryptography, security co-processors, key management, a trusted computing base (TCB), support for trusted booting, manageable access control models (ACM), authentication for digital signatures, secure updates to remove vulnerabilities after product launch, encrypted network communications and distributed security models such as Kerberos (Watson, 2012, p.16). Of course, at the center of the operating system is the kernel, which most modern operating systems can attribute to MIT’s Multics project, where hardware, the OS kernel and applications are all separated from one another to provide a...