Computer viruses pose a very real threat to this technological age. As our dependence on computers increases so does the incidence of computer virus infection. Like their biological counterparts, complete eradication is virtually impossible. Thus all computer viruses which have been injected into the public domain still exist. This coupled with the fact that new viruses are being discovered every day is resulting in a massive escalation of computer virus incidence. Computer viruses covertly enter the system and systematically take control, corrupt and destroy. New viruses appear each day that circumvent current means of detection, entering the most secure of systems. Anti-Virus software writers find themselves fighting a battle they cannot win: for every hole that is plugged, another leak appears. Presented in this thesis is both method and apparatus for an Anti-Virus System which provides a solution to this serious problem. It prevents the corruption, or destruction of data, by a computer virus or other hostile program, within a computer system. The Anti-Virus System explained in this thesis will guarantee system integrity and virus containment for any given system. Unlike other anti-virus techniques, security can be guaranteed, as at no point can a virus circumvent, or corrupt the action of the Anti-Virus System presented. It requires no hardware modification of the computer or the hard disk, nor software modification of the computer's operating system. Whilst being largely transparent to the user, the System guarantees total protection against the spread of current and future viruses.

This research report gives a general description of virtual memory systems. The mechanisms and policies and their effect on the operation and efficiency of virtual memory are explained. A virtual memory using a real time virtual address decoder, to decode a 32 bits of virtual address for the secondary memory to obtain the primary address location discussed. The decoder is developed with the use of associative or content-addressable memories. Replacement algorithms, used for selecting the pages of the main memory to be replaced, are described. The hardware implementation of the least recently used and least often used replacement policies using associative memories is presented.

Approved for public release; distribution is unlimited / A computer security virtual lab architecture was developed and tested for functionality and performance. Four Dell PowerEdge 1650, dual processor, blade servers were configured as host machines with VMware and VNC running on a Linux RedHat 9 Kernel. An Apache-Tomcat web server was configured as the external interface to lab users. Web content was created, the site was secured with SSL, and Java Servlet functionality was enabled. Host machine performance was tested under various load conditions. Analysis indicated that, for our architecture, that the average host machine CPU load was [about]12 % while the average memory load was [about]33 %. We conclude that for the cost and space requirements of 5 1U blade servers we have configured an equivalent 20 computer lab. Performance tests show that the virtual lab could scale easily from 4 - 30 computers. / 1st Lieutenant, Turkish Army / 1st Lieutenant, Turkish Army

The prominence of the internet and networked computing has driven research efforts into providing support for heterogeneous computing platforms. This has been exemplified by the emergence of virtual machines, such as the Java virtual machine. Unfortunately, most virtual computing platforms come with a performance penalty. This dissertation investigates a new approach for providing virtual computing platforms through the use of reconfigurable computing devices and hardware/software co-design. Traditionally, when designing a hardware/software solution, instance specific methods are used to iterate towards a solution that satisfies the requirements. This is not an ideal approach as the costs involved with integrating hardware and software components are significant. This technique demotes the interface between the hardware and software, often resulting in major complications at the integration stage. These problems can be avoided through adherence to a sound methodology which the co-design process follows. This dissertation examines the original concept of using hardware/software co-design and reconfigurable computing as a means of providing virtual machine platforms. Specifically the contributions include an advancement towards a new general computing paradigm and architecture; guidelines and several algorithms for applying the general hardware/software co-design process to the specific virtual machine class of problems; and an assessment of the potential advantages of using co-design as an implementation approach for virtual machines. These are applied to the Java virtual machine and simulated for insights into the potential benefits, requirements, and caveats of co-design for virtual machines. This research demonstrates that using hardware/software co-design as described specifically for virtual machines, the solution can offer performance benefits over a software-only solution. These performance increases will be shown to be dependent upon several factors such as the application itself and the underlying architectural features. This dissertation will promote and give evidence that reconfigurable computing can be used for more general purpose computing and not just for specific problem instances. / Graduate

Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Computer Science, 2009. / Includes bibliographical references.

Thesis (M.S.E.)--University of Washington, 1993. / Includes bibliographical references (leaves [116]-119).

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaf 76).

Thesis (M.S. in Computer Science)--Naval Postgraduate School, Sept. 2004. / Thesis advisor(s): Richard M. Harkins. Includes bibliographical references (p. 75-76). Also available online.