The current strategy to computer networking is to increase the accessibility that legitimate users have to their respective systems and to distribute functionality. This creates a more efficient working environment, users may work from home, organisations can make better use of their computing power. Unfortunately, a side effect of opening up computer systems and placing them on potentially global networks is that they face increased threats from uncontrolled access points, and from eavesdroppers listening to the data communicated between systems. Along with these increased threats the traditional ones such as disgruntled employees, malicious software, and accidental damage must still be countered. A comprehensive integrated security system ( CISS ) has been developed to provide security within the Open Systems Interconnection (OSI) and Open Distributed Processing (ODP) environments. The research described in this thesis investigates alternative methods for its implementation and its optimisation through partial implementation within hardware and software and the investigation of mechanismsto improve its security. A new deployment strategy for CISS is described where functionality is divided amongst computing platforms of increasing capability within a security domain. Definitions are given of a: local security unit, that provides terminal security; local security servers that serve the local security units and domain management centres that provide security service coordination within a domain. New hardware that provides RSA and DES functionality capable of being connected to Sun microsystems is detailed. The board can be used as a basic building block of CISS, providing fast cryptographic facilities, or in isolation for discrete cryptographic services. Software written for UNIX in C/C++ is described, which provides optimised security mechanisms on computer systems that do not have SBus connectivity. A new identification/authentication mechanism is investigated that can be added to existing systems with the potential for extension into a real time supervision scenario. The mechanism uses keystroke analysis through the application of neural networks and genetic algorithms and has produced very encouraging results. Finally, a new conceptual model for intrusion detection capable of dealing with real time and historical evaluation is discussed, which further enhances the CISS concept.

This thesis considers the current requirements for security in European healthcare establishments. Information Technology is being used increasingly by all areas of healthcare, from administration to clinical treatment and this has resulted in increased dependence upon computer systems by healthcare staff. The thesis looks at healthcare security requirements from the European perspective. An aim of the research was to develop security guidelines that could be used by healthcare establishments to implement a common baseline standard for security. These guidelines represent work submitted to the Commission of European Communities SEISMED (Secure Environment for Information Systems in Medicine) project, with which the research programme was closely linked. The guidelines were validated by implementing them with the Plymouth and Torbay Health Trust. The thesis also describes the development of a new management methodology and this was developed to allow the smooth implementation of security within healthcare establishments. The methodology was validated by actually using it within the Plymouth and Torbay Health Authority to implement security countermeasures. A major area of the research was looking at the use of risk analysis and reviewing all the known risk analysis methodologies. The use of risk analysis within healthcare was also considered and the main risk analysis methods used by UK healthcare establishments were reviewed. The thesis explains why there is a need for a risk analysis method specially developed for healthcare. As part of the research a new risk analysis method was developed, this allows healthcare establishments to determine their own security requirements. The method was also combined with the new management methodology that would determine any implementional problems. The risk analysis methodology was developed into a computerised prototype, which demonstrated the different stages of the methodology.

In this dissertation, we focus on dynamic analyses that examine the data handled by programs and operating systems in order to divine the undocumented constraints and implementation details that determine their behavior in the field. First, we introduce a novel technique for uncovering the constraints actually used in OS kernels to decide whether a given instance of a kernel data structure is valid. Next, we tackle the semantic gap problem in virtual machine security: we present a pair of systems that allow, on the one hand, automatic extraction of whole-system algorithms for collecting information about a running system, and, on the other, the rapid identification of “hook points” within a system or program where security tools can interpose to be notified of security-relevant events. Finally, we present and evaluate a new dynamic measure of code similarity that examines the content of the data handled by the code, rather than the syntactic structure of the code itself. This problem has implications both for understanding the capabilities of novel malware as well as understanding large binary code bases such as operating system kernels.

No description available.

No description available.

No description available.

Recent revisions to Articles 9 and 1 of the Uniform Commercial Code (the "UCC") have proposed new intangible secured financing choice of law rules. These choices of law rules contain rules that represent all three major schools of thought in the field of conflicts of laws: multilateralism, substantivism and unilateralism. This thesis examines the new rules by analysing them in the context of the strengths and weakness of these schools of thought and in light of the requirements of a secured financing system. On the whole the strong mulitlateralist focus of the majority of the rules provides a solid basis for the UCC's choice of law provisions. The elimination of the rule that was based on a unilateralist basis is a logical improvement. However, the inclusion of a rule, §9-307(c), with a substantivist basis introduces an element of uncertainty into the system and should be removed.

In the second chapter, the notion of a social secret sharing (SSS) scheme is introduced in which shares are allocated based on a player's reputation and the way she interacts with other parties. In other words, this scheme renews shares at each cycle without changing the secret, and it allows the trusted parties to gain more authority. Our motivation is that, in real-world applications, components of a secure scheme have different levels of importance (i.e., the number of shares a player has) and reputation (i.e., cooperation with other parties). Therefore, a good construction should balance these two factors accordingly. In the third chapter, a novel socio-rational secret sharing (SRS) scheme is introduced in which rational foresighted players have long-term interactions in a social context, i.e., players run secret sharing while founding and sustaining a public trust network. To motivate this, consider a repeated secret sharing game such as sealed-bid auctions. If we assume each party has a reputation value, we can then penalize (or reward) the players who are selfish (or unselfish) from game to game. This social reinforcement stimulates the players to be cooperative in the secret recovery phase. Unlike the existing protocols in the literature, the proposed solution is stable and it only has a single reconstruction round. In the fourth chapter, a comprehensive analysis of the existing dynamic secret sharing (DSS) schemes is first provided. In a threshold scheme, the sensitivity of the secret and the number of players may fluctuate due to various reasons. Moreover, a common problem with almost all secret sharing schemes is that they are ``one-time'', meaning that the secret and shares are known to everyone after secret recovery. We therefore provide new techniques where the threshold and/or the secret can be changed multiple times to arbitrary values after the initialization. In addition, we introduce a new application of dynamic threshold schemes, named sequential secret sharing (SQS), in which several secrets with increasing thresholds are shared among the players who have different levels of authority. In the fifth chapter, a cryptographic primitive, named multicomponent commitment scheme (MCS) is proposed where we have multiple committers and verifiers. This new scheme is used to construct different sealed-bid auction protocols (SAP) where the auction outcomes are defined without revealing the losing bids. The main reason for constructing secure auctions is the fact that the values of the losing bids can be exploited in future auctions and negotiations if they are not kept private. In our auctioneer-free protocols, bidders first commit to their bids before the auction starts. They then apply a decreasing price mechanism to define the winner and selling price in an unconditionally secure setting.

This thesis investigates four different aspects of information security management: challenges faced by security practitioners, interactive collaborations among security practitioners and other stakeholders, diagnostic work performed by security practitioners during the response to incidents, and factors that impact the adoption of an intrusion detection system in one organization. Our approach is based on qualitative analyzes of empirical data from semi-structured interviews and participatory observation. For each theme under study, the contributions of the qualitative analysis are twofold. First, we provide a richer understanding of the main factors that affect the security within organizations. Second, equipped with this richer understanding, we provide recommendations on how to improve security tools, along with opportunities for future research. Our findings contribute to the understanding of the human, organizational, and technological factors that affect security in organizations and the effectiveness of security tools. Our work also highlights the need for continued refinement of how factors interplay by obtaining more rich data (e.g., contextual inquiry), and the need to generalize and validate these findings through other sources of information to study how these factors interplay (e.g., surveys).

Thesis (MEng (Electro Sys))--University of South Australia, 1999