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.

When adding Confidentiality, Integrity and Availability (CIA) to a multi-user VoIP (Voice over IP) system, performance and quality are at risk. The aim of this study is twofold. Firstly, it describes current methods suitable to secure voice streams within a VoIP system and make them available in an Asterisk-based VoIP environment. (Asterisk is a well established, open-source, TDM/VoIP PBX.) Secondly, this study evaluates the performance cost incurred after implementing each security method within the Asterisk-based system, using a special testbed suite, named DRAPA, which was developed expressly for this study. The three security methods implemented and studied were IPSec (Internet Protocol Security), SRTP (Secure Real-time Transport Protocol), and SIAX2 (Secure Inter-Asterisk eXchange 2 protocol). From the experiments, it was found that bandwidth and CPU usage were significantly affected by the addition of CIA. In ranking the three security methods in terms of these two resources, it was found that SRTP incurs the least bandwidth overhead, followed by SIAX2 and then IPSec. Where CPU utilisation is concerned, it was found that SIAX2 incurs the least overhead, followed by IPSec, and then SRTP.

This thesis examines distributed authentication in the process of controlling computing resources. We investigate user sign-on and two of the main authentication technologies that can be used to control a resource through authentication and providing additional security services. The problems with the existing sign-on scenario are that users have too much credential information to manage and are prompted for this information too often. Single Sign-On (SSO) is a viable solution to this problem if physical procedures are introduced to minimise the risks associated with its use. The Generic Security Services API (GSS-API) provides security services in a manner in- dependent of the environment in which these security services are used, encapsulating security functionality and insulating users from changes in security technology. The un- derlying security functionality is provided by GSS-API mechanisms. We developed the Secure Remote Password GSS-API Mechanism (SRPGM) to provide a mechanism that has low infrastructure requirements, is password-based and does not require the use of long-term asymmetric keys. We provide implementations of the Java GSS-API bindings and the LIPKEY and SRPGM GSS-API mechanisms. The Secure Authentication and Security Layer (SASL) provides security to connection- based Internet protocols. After finding deficiencies in existing SASL mechanisms we de- veloped the Secure Remote Password SASL mechanism (SRP-SASL) that provides strong password-based authentication and countermeasures against known attacks, while still be- ing simple and easy to implement. We provide implementations of the Java SASL binding and several SASL mechanisms, including SRP-SASL.

M.Sc. (Information Technology) / Please refer to full text to view abstract

Ph.D. / Many organisations are starting to make large parts of their information resources publicly accessible. For example, many organisations publish information using the Internet. Some organisations allow non-employees to connect to their systems and retrieve information - many banks allow customers to retrieve account statements via the Internet. There is a trend towards more open information systems and more distributed processing such as client/server processing. The above are just some of the trends in computer information processing that creates new and complex problems in providing information systems that are both secure and manageable. To add to the complexity of the information security problem, organisations use the Internet to conduct some of their business and use many different applications, each with its own unique access control mechanisms. Central management of information security in a heterogeneous and distributed environments, such as the Internet has become a nightmare. There is a need for an information security model that will allow organisations to make use of the new trends in information processing, but still have confidence that they have adequate security and that the management of their information security systems is fairly easy. In this thesis we propose a model that satisfies the above requirements. We call this model the Intelligent Security Agent Model (ISAM). The ISAM model is based on two technologies: intelligent software agents and distributed objects. The main component of the model is Intelligent Security Agents that act as security brokers for its users in a distributed environment. In chapter 2 of the thesis, we design an Intelligent Security Agent which provides various information security services in open client/server environments. The Intelligent Security Agent Model addresses certain problems/requirements, such as single sign-on, in information security. These problems and possible solutions are described in chapter 4 to chapter 10 of this thesis. An Intelligent Security Agent must be protected from unauthorised modification, theft, etc. Chapter 3 shows how an Intelligent Security Agent is secured by implementing it as a distributed object. We show that the combination of intelligent software agents and distributed objects creates an agent that was not possible before, and solves many information security problems.In short, this thesis documents the results of a study in computer information security. The result of the study is a new information security model in which intelligent software agents and distributed objects are combined to create a security agent which acts on behalf of a user in open environments such as client/server systems and the Internet. The agent provides a set of services to its user and handles all information security related requests on behalf of its user.

The importance of information in business today has made the need to properly secure this asset evident. Information security has become a responsibility for all managers of an organization. To better support more efficient management of information security, timely information security management information should be made available to all managers. Smaller organizations face special challenges with regard to information security management and reporting due to limited resources (Ross, 2008). This dissertation discusses a Framework for Information Security Management Information (FISMI) that aims to improve the visibility and contribute to better management of information security throughout an organization by enabling the provision of summarized, comprehensive information security management information to all managers in an affordable manner.

M.Sc.(Computer Science) / The aim of this dissertation (referred to as thesis in the rest of the document) is to present authentication techniques that can be used to provide secure Internet commerce. The thesis presents techniques that can be used to authenticate human users at logon, as well as techniques that are used to authenticate user's PC and the host system during communication. In so doing, the thesis presents cryptography as the most popular approach to provide information security. Chapter 1 introduces the authentication problem, the purpose and the structure of the thesis. The inadequate security of the Internet prevents companies and users to conduct commerce over the Internet. Authentication is one of the means of providing secure Internet commerce. - Chapter 2 provides an overview of the Internet by presenting the Internet history, Internet infrastructure and the current services that are available on the Internet. The chapter defines Internet commerce and presents some of the barriers to the Internet commerce. Chapter 3 provides an overview of network and internetwork security model. The purpose of this chapter is to put authentication into perspective, in relation to the overall security model. Security attacks, security services and security mechanisms are defined in this chapter. The IBM Security Architecture is also presented. Chapter 4 presents cryptography as the popular approach to information security. The conventional encryption and public-key encryption techniques are used to provide some of the security services described in chapter 3. Chapter 5 presents various schemes that can be used to provide computer-to-computer authentication. These schemes are grouped into the following authentication functions: message encryption, cryptographic checksums, hash functions and digital signatures. Chapter 6 differentiates between one-way authentication schemes and mutual authentication schemes. The applicability of each approach depends on the communicating parties. Chapter 7 presents some of the popular and widely used open-systems technologies Internet protocols, which employ some of the schemes discussed in chapter 5 and chapter 6. These include the SSL, PCT, SHTTP, Kerberos, SESAME and SET. Chapter 8 discusses some of the enabling technologies that are used to provide human user authentication in a computer system. The password technology, the biometric technologies and the smart card technology are discussed. The considerations of selecting a specific technology are also discussed. Chapter 9 presents some of the techniques that can be used to authentication Internet users (human users) over the Internet. The techniques discussed are passwords, knowledge-based technique, voice recognition, smart cards, cellular based technique, and the technique that integrates Internet banking. Chapter 10 defines criteria on which the Internet user authentication techniques presented in chapter 9 can be measured against. The evaluation of each of the techniques is made against the specified criteria. In fact, this chapter concludes the thesis. Chapter 11 provides case studies on two of the techniques evaluated in chapter 10. Specifically, the insurance case study and the medical aid case studies are presented.

D.Litt. et Phil. / It is said that computer security is like getting into bed with an elephant. You know you have a problem, but you can't get your arms around it! Looking at security from a distributed point of view makes this elephant seem much bigger! The growth of the Internet (see chapter 2) is also not very comforting to computer security specialists. Companies want to start utilising the Internet for their business transactions, while the man on the street wants to use it for what they deem necessary or convenient. It is becoming more and more common placed to buy items from virtual storefronts by making use of the Internet. [17,20,23] Literature, as well as the World Wide Web has supplied us with information [34] regarding the "war" between the IT Security Professional and the hacker community. It is quite surprising to see the large number of hacker sites on the Internet [15,16,21] that publish information regarding hacked sites, as well as tools and techniques that can assist almost anyone in accomplishing some of these sometimes, daring feats. If this information is studied and if we keep in mind that some of the more serious hacking attempts are being kept secret for reasons like loss of business or credibility, it might be deduced that the hacker community is always a step or two ahead of Security Professionals. It is the purpose of this thesis to present a model that will ensure secure, anonymous communication across the Internet This model is not aimed at replacing current technologies. It merely attempts to provide an alternative method for safe communication across public networks, like the Internet. The model will make use of a number of existing technologies in conjunction with one another to achieve its goal of secure, anonymous communication. The technologies that will be used and how will be discussed briefly in this chapter.

The motivation for this study argued that current information security ed- ucation systems are inadequate for educating all users of computer systems world wide in acting securely during their operations with information sys- tems. There is, therefore, a pervasive need for information security knowledge in all aspects of modern life. E-Learning 2.0 could possi- bly contribute to solving this problem, however, little or no knowledge currently exists regarding the suitability and practicality of using such systems to infer information security knowledge to learners.

Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.