Online communities are growing at a phenomenal rate and with the large number of users these communities contain, attackers are drawn to exploit these users. Denial of information (DoI) attacks and information leakage attacks are two popular attacks that target users on online communities. These information based attacks are linked by their opposing views on low-quality information. On the one hand denial of information attacks which primarily use low-quality information (such as spam and phishing) are a nuisance for information consumers. On the other hand information leakage attacks, which use inadvertently leaked information, are less effective when low-quality information is used, and thus leakage of low-quality information is prefered by private information producers. In this dissertation, I introduce techniques for preventing abuse against these attacks in online communities using meta-model classification and information unification approaches, respectively. The meta-model classification approach involves classifying the ``connected payload" associated with the information and using the classification result for the determination. This approach allows for detection of DoI attacks in emerging domains where the amount of information may be constrained. My information unification approach allows for modeling and mitigating information leakage attacks. Unifying information across domains followed by a quantificiation of the information leaked, provides one of the first studies on users' susceptibality to information leakage attacks. Further, the modeling introduced allows me to quantify the reduced threat of information leakage attacks after applying information cloaking.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

M. Tech. Information Networks / The increasing sophistication of information security threats and the ever-growing body of regulation has made information security a critical function in higher education institutions. Research was undertaken to investigate the implementation of information security strategies in higher education institutions in South Africa. This thesis investigates the following: How will the formulation of an information security strategy improve information security in higher education institutions; in what way should higher education institutions employ information security policies in order to improve information security; and how may the adoption of information security framework create information security awareness among employees in higher education institutions?

published_or_final_version / abstract / toc / Computer Science and Information Systems / Master / Master of Philosophy

No description available.

Mobile ad hoc networks (MANETs) are generating much interest both in academia and the telecommunication industries. The principal attractions of MANETs are related to the ease with which they can be deployed due to their infrastructure-less and decentralized nature. For example, unlike other wireless networks, MANETs do not require centralized infrastructures such as base stations, and they are arguably more robust due to their avoidance of single point of failures. Interestingly, the attributes that make MANETs attractive as a network paradigm are the same phenomena that compound the challenge of designing adequate security schemes for these innovative networks. / One of the challenging security problems is the issue of certificate revocation in MANETs where there are no on-line access to trusted authorities. In wired network environments, when certificates are to be revoked, certificate authorities (CAs) add the information regarding the certificates in question to certificate revocation lists (CRLs) and post the CRLs on accessible repositories or distribute them to relevant entities. In purely ad hoc networks, there are typically no access to centralized repositories or trusted authorities; therefore the conventional method of certificate revocation is not applicable. / Another challenging MANET security problem is the issue of secure routing in the presence of selfish or adversarial entities which selectively drop packets they agreed to forward; and in so doing these selfish or adversarial entities can disrupt the network traffic and cause various communication problems. / In this thesis, we present two security protocols we developed for addressing the above-mentioned MANET security needs. The first protocol is a decentralized certificate revocation scheme which allows the nodes within a MANET to have full control over the process of certificate revocation. The scheme is fully contained and it does not rely on any input from centralized or external entities such as trusted CAs. The second protocol is a secure MANET routing scheme we named Robust Source Routing (RSR). In addition to providing data origin authentication services and integrity checks, RSR is able to mitigate against intelligent, colluding malicious agents which selectively drop or modify packets they are required to forward.

Ecommerce refers to the buying and selling of products and services electronically via the Internet and other computer networks (Electronic Commerce 2011). The critical components of ecommerce are a well designed website and a merchant account for payment by the customer (Ecommerce critical components 2008). Merchants that sell their products and services via the Internet have a competitive edge over those that do not. It is therefore becoming common practice for both small and large business to transact electronically. With the vast opportunities, new risks and vulnerabilities are introduced. Consumers are reluctant to transact electronically because of the fear of unauthorized access and interception of confidential information (Online Banking Concerns 2011). Other fears include the changing of data with malicious intent, denial of use, hacking, deliberate disclosure of confidential information and e-mail associated risks (Safeena, Abdulla & Date 2010). The use of technology such as encryption and decryption has not adequately addressed these problems because fraudsters have found new and sophisticated methods of attaining consumer information illegally. Phishing is one such method. Phishing results in identity theft and financial fraud when the fraudster tricks the online users into giving their confidential information like passwords, identity numbers, credit card number and personal information such as birthdates and maiden names. The fraudster will then use the information to impersonate the victim to transfer funds from the victim‟s account or use the victim‟s information to make purchases (Srivastava 2007). Since 2002, many laws passed in South Africa have attempted to allay fears so that consumers can conduct business electronically with confidence. The following legislation aims to protect consumers: - The Electronic Communications and Transactions Act (Republic of South Africa 2002). - The Consumer Protection Act (Republic of South Africa 2008). - The Protection of Personal Information Bill which is expected to be passed in 2011 (Republic of South Africa 2009). This research aims to examine the extent to which these legislation can address the security concerns of consumers. The researcher is also interested in ascertaining how knowledgeable consumers are on these legislation and what their attitudes are towards their personal information security. / Thesis (M.Com.)-University of KwaZulu-Natal, Westville, 2011.

Operating system security has become a growing concern these days. As the complexity of software layers increases, the vulnerabilities that can be exploited by adversaries increases. Rootkits are gaining much attention these days in cyber-security. Rootkits are installed by an adversary after he/she gains elevated access to the computer system. Rootkits are used to maintain a consistent undetectable presence in the computer system and help as a toolkit to hide all the malware activities from the system administrator and anti-malware tools. Current defense mechanism used to prevent such activities is to strengthen the OS kernel and fix the known vulnerabilities. Software tools are developed at the OS or virtual machine monitor (VMM) levels to monitor the integrity of the kernel and try to catch any suspicious activity after infection. Recognizing the failure of software techniques and attempting to solve the endless war between the anti-rootkit and rootkit camps, in this thesis, we propose an autonomic architecture called SHARK, or Secure Hardware support Against RootKits. This new hardware architecture provides system-level security against the stealth activities of rootkits without trusting the entire software stack. It enhances the relationship of the OS and hardware and rules out the possibility of any hidden activity even when the OS is completely compromised. SHARK proposes a novel hardware manager that provides secure association with every software context making use of hardware resources. It helps system administrators to obtain feedback directly from the hardware to reveal all running processes. This direct feedback makes it impossible for rootkits to conceal running software contexts from the system administrator. We emulated the proposed architecture SHARK by using Bochs hardware simulator and a modified Linux kernel version 2.6.16.33 for the proposed architectural extension. In our emulated environment, we installed several real rootkits to compromise the kernel and concealed malware processes. SHARK is shown to be very effective in defending against a variety of rootkits employing different software schemes. Also, we performed performance analysis using SIMICS simulations and the results show a negligible overhead, making the proposed solution very practical.

In the first essay, I examine value created through external acquisition of nascent technology innovation. External acquisition of new technology is a growing trend in the innovation process, particularly in high technology industries, as firms complement internal efforts with aggressive acquisition programs. Yet, despite its importance, there is little empirical research on the timing of acquisition decisions in high technology environments. I examine the impact of target age on value created for the buyer. Applying an event study methodology to technology acquisitions in the telecommunications industry from 1995 to 2001, empirical evidence supports acquiring early in the face of uncertainty. The equity markets reward the acquisition of younger companies. In sharp contrast to the first essay, the second essay examines the diffusion of negative innovations. While destruction can be creative, certainly not all destruction is creative. Some is just destruction. I examine two fundamentally different paths to information security compromise an opportunistic path and a deliberate path. Through a grounded approach using interviews, observations, and secondary data, I advance a model of the information security compromise process. Using one year of alert data from intrusion detection devices, empirical analysis provides evidence that these paths follow two distinct, but interrelated diffusion patterns. Although distinct, I find empirical evidence that these paths both converge and escalate. Beyond the specific findings in the Internet security context, the study leads to a richer understanding of the diffusion of negative technological innovation. In the third essay, I build on the second essay by examining the effectiveness of reward-based mechanisms in restricting the diffusion of negative innovations. Concerns have been raised that reward-based private infomediaries introduce information leakage which decreases social welfare. Using two years of alert data, I find evidence of their effectiveness despite any leakage which may be occurring. While reward-based disclosures are just as likely to be exploited as non-reward-baed disclosures, exploits from reward-based disclosures are less likely to occur in the first week after disclosure. Further the overall volume of alerts is reduced. This research helps determine the effectiveness of reward mechanisms and provides guidance for security policy makers.