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.

D.Econ.

Devido à importância dos firewalls para proteção de redes de computadores, muito se estuda no sentido do aprimoramento das técnicas de proteção e no desenvolvimento de novas técnicas para serem utilizadas na análise destes. Com enfoque neste tema, esta dissertação trata a respeito da viabilidade da técnica de injeção de pacotes e observação dos resultados para analisar o comportamento de firewalls de rede para a pilha TCP/IP, resultando em uma técnica alternativa para análise de firewalls. Para mostrar a validade da técnica foi proposta uma arquitetura e, como prova de conceito, foi implementado um protótipo do sistema de análise. Foram também efetuados alguns testes. A técnica de injeção de pacotes e observação dos resultados mostrou-se viável para algumas situações. Para outras, são necessárias estudos adicionais para redução da explosão combinatória. / Due to the importance of the firewalls for protection of network computers, a lot of studies has been done in order of the improvement of the protection techniques and in the development of new techniques to be used in the analysis of them. With focus in this theme, this thesis considers the viability of the technique of injection of packages and observation of the results to analyze the behavior of network firewalls for stack TCP/IP, resulting in an alternative technique for analysis of firewalls. To show the validity of the technique an architecture was proposed and, as a concept proof, a prototype of the analysis system was implemented. Also was implemented some tests. The technique of injection of packages and observation of the results reveled viable for some situations. For others, addictionals studies are necessary for reduction of the combinatory explosion.

Devido à importância dos firewalls para proteção de redes de computadores, muito se estuda no sentido do aprimoramento das técnicas de proteção e no desenvolvimento de novas técnicas para serem utilizadas na análise destes. Com enfoque neste tema, esta dissertação trata a respeito da viabilidade da técnica de injeção de pacotes e observação dos resultados para analisar o comportamento de firewalls de rede para a pilha TCP/IP, resultando em uma técnica alternativa para análise de firewalls. Para mostrar a validade da técnica foi proposta uma arquitetura e, como prova de conceito, foi implementado um protótipo do sistema de análise. Foram também efetuados alguns testes. A técnica de injeção de pacotes e observação dos resultados mostrou-se viável para algumas situações. Para outras, são necessárias estudos adicionais para redução da explosão combinatória. / Due to the importance of the firewalls for protection of network computers, a lot of studies has been done in order of the improvement of the protection techniques and in the development of new techniques to be used in the analysis of them. With focus in this theme, this thesis considers the viability of the technique of injection of packages and observation of the results to analyze the behavior of network firewalls for stack TCP/IP, resulting in an alternative technique for analysis of firewalls. To show the validity of the technique an architecture was proposed and, as a concept proof, a prototype of the analysis system was implemented. Also was implemented some tests. The technique of injection of packages and observation of the results reveled viable for some situations. For others, addictionals studies are necessary for reduction of the combinatory explosion.

Information constitutes one of an organisation’s most valuable assets. It provides the modern organisation with a competitive edge and in some cases, is a requirement merely to survive. An organisation has to protect its information but due to the distributed, networked environment of today, faces a difficult challenge; it has to implement a system of information security management. Software applications can provide significant assistance in managing information security. They can be used to provide for centralised feedback of information security related activities as well as for centralised configuration activities. Such an application can be used in enforcing compliance to the organisation’s information security policy document. Currently there are a number of software products that provide this function in varying measures. In this research the major players in this space were examined to identify the features commonly found in these systems, and where they were lacking in terms of affordability, flexibility and scalability. A framework for an information security management application was defined based on these features and requirements and incorporating the idea of being affordable, but still flexible and extendable. This shifted the focus from attempting to provide a comprehensive list of interfaces and measurements into general information security related activities, to focusing on providing a generic tool that could be customised to handle any information fed back to it. The measurements could then be custom-developed as per the needs of the organisation. This formed the basis on which the prototype information security management application (InfoSure) was developed. / Prof. S.H. Solms

Throughout the years, computer networks have grown in size and complexity. This growth attributed to the need for network security. As more and more people use computers and the Internet, more confidential documentation are being kept on computers and sent to other locations over a network. To implement network security, the security administrator should firstly identify all the needs, resources, threats and risks of the organisation to ensure that all areas of the network is included within the network security policy. The network security policy contains, amongst others, the information security services needed within the organisation’s network for security. These information security services can be implemented via many different security mechanisms. Firewalls are but one of these security mechanisms. Today, firewalls are implemented in most organisations for network security purposes. The author, however, feels that the implementation of only a firewall is not enough. Tools such as log file analysers and risk analysers can be added to firewall technology to investigate and analyse the current network security status further for an indication of network failure or attacks not easily detectable by firewalls. Firewalls and these tools do, however, also have their own problems. Firewalls rarely use the information stored within its log files and the risk handling services provided are not very effective. Most analysis tools use only one form of log file as input and therefore report on only one aspect of the network’s security. The output of the firewalls is rarely user-friendly and is often not real-time. The detection of security problems is consequently a very difficult task for any security administrator. To address the problems, the researcher has developed a prototype that improves on these problems. The firewall analyser (FA) is a prototype of an An audit and risk handling prototype for firewall technology Page iii analysis tool that performs log file- and risk analysis of the underlying networks of the organisation. Although the prototype represents only an example of the functionality added to a firewall, it illustrates the concept of the necessity and value of implementing such a tool for network security purposes. The FA solves the problems found in firewalls, log file- and risk analysis tools by reporting on the latest security status of the network through the use of a variety of log files. The FA uses not only the firewall log files as input to cover a greater area of the network in its analysis process, but also Windows NT log files. The real-time reports of the FA are user-friendly and aid the security administrator immensely in the process of implementing and enforcing network security. / Eloff, J.H.P., Prof.

No description available.

With the dramatic expansion of computers and communication networks, computer crimes, such as threatening letters, fraud, and theft of intellectual property have been growing at a dreadful rate. The increasing frequency of malicious computer attacks on government agencies and Internet businesses has caused severe economic waste and unique social threats. The problems of protecting data and information on computers and communication networks has become even more critical and challenging, since the widespread adoption of the Internet and the Web. Consequently, it is very urgent to design an integrated network-security architecture so as to make information safer, proactively or reactively defeat any network attack, make attackers accountable, and help the law enforcement system to collect the forensic evidences. Among a variety of attacks on computer servers or communication networks, a prevalent, famous, and serious network-security subject is known as "Denial of Service" (DoS) or "Distributed Denial of Service" (DDoS) attacks. According to an investigation on computer crime conducted by CSI/FBI in 2003, Internet DoS/DDoS have increased in frequency, severity, and sophistication, and have caught international attentions to the vulnerability of the Internet. DoS/DDoS attacks consume the resources of a remote host or network, thereby denying or degrading service to legitimate users. Such attacks are among the hardest security problems to address because they are simple to implement, difficult to prevent, and very difficult to trace. Therefore, this dissertation will firstly concentrate on how to resolve these troublesome DoS/DDoS problems. This is considered as the first step to overcome generic network security problems, and to achieve the final goal for accomplishing a total solution of network security. Instead of tolerating DoS/DDoS attacks by mitigating their effect, to trace back the attacking source for eliminating the attacker is an aggressive and better approach. However, it is difficult to find out the true attacking origin by utilizing the incorrect source IP address faked by the attacker. Accordingly, this dissertation will aim at conquering this representative network security problem, i.e. DoS/DDoS attacks, with IP traceback, and designing an optimal IP traceback. IP traceback ¡X the ability to trace IP packets to their origins¡Xis a significant step toward identifying, and thus stopping, attackers. A promising solution to the IP traceback is probabilistic packet marking (PPM). This traceback approach can be applied during or after an attack, and it does not require any additional network traffic, router storage, or packet size increase. Therefore, the IP traceback research on countering DoS/DDoS attacks will be based on PPM scheme. In this dissertation, three outstanding improvements among four PPM criteria¡Xthe convergency, the computational overhead, and the incomplete PPM deployment problem¡Xhas been achieved. PPM-NPC is proposed to improve the PPM convergency and computational overhead. With non-preemptively compensation, the probability of each marked packet arrived at the victim equals its original marking probability. Therefore, PPM-NPC will efficiently achieve the optimal convergent situation by simply utilizing a 2-byte integer counter. Another better scheme, CPPM, is also proposed, such that the marked packets can be fully compensated as well while they are remarked. With CPPM, the probability of each marked packet arrived at the victim will also equal its original marking probability. Consequently, CPPM will achieve the optimal convergent situation efficiently as well. Furthermore, RPPM-NPC is presented to advance the accuracy of a reconstructed path in an incomplete PPM deployment environment by correcting and recovering any discontinuous individual transparent router and any segment of consecutive double transparent routers. This scheme may also reduce the deployment overhead without requiring the participation of all routers on the attack path. Except for these improved criteria, PPM robustness, some weak assumptions in PPM, and a few unsolved problems for PPM, e.g. reflective DDoS attacks, will also be improved in the future. It is also interesting in combining other network security researches, such as IDS, system access control mechanism, etc., for constructing a more complete network security architecture. Therefore, this research hereby is done in order to completely resolve the troublesome flood-style DoS/DDoS problems, and as the basis for accomplishing a total solution of network security.

Electronic commerce is a large and ever growing industry. Online transactions are returning ever-growing revenues to electronic merchants. The e-commerce industry is still facing a range of problems concerning the process of completion of online transactions. Such problems are connected to consumer fears dealing with the identity of online merchants, their security pre- cautions and methods for accepting online payments. This thesis develops and presents a Mutual Authentication Model (MAM), which addresses the problem of mutual authentication between online shoppers and merchants. The model combines existing technologies in the eld of cryp- tography, as well as the use of digital signatures and certi cates. This is done in a speci c manner as for the model to achieve mutual authentication between communicating parties, in an online transactions. The Mutual Authentication Model provides a process through which an online shopper can be quickly and transparently equipped with a digital identi cation, in the form of a digital certi cate of high trust, in order for this shopper to participate in an authen- ticated transaction within the MAM. A few of the advantages of the developed model include the prospect of decreased online credit fraud, as well as an increased rate of completed online transactions. / Prof. S.H. von Solms

LL.M. / Organisations are being placed under increased pressure by means of new laws, regulations and standards, to ensure that adequate information security exists within the organisation. The King II report introduced corporate South Africa to the concept of information security in 2002. In the same year the Electronic Communications and Transactions Act 25 of 2002 addressed certain technical information security issues such as digital signatures, authentication, and cryptography. Therefor, South Africa is increasingly focussing its attention on information security. This trend is in line with the approach taken by the rest of the international community, who are giving serious consideration to information security and the governance thereof. As organisations are waking up to the benefits offered by the digital world, information security governance is emerging as a business issue pivotal within the e-commerce environment. Most organisations make use of electronic communications systems such as e-mail, faxes, and the world-wide-web when performing their day-to-day business activities. However, all electronic transactions and communications inevitably involve information being used in one form or another. It may therefor be observed that information permeates every aspect of the business world. Consequently, the need exists to have information security governance in place to ensure that information security prevails. However, questions relating to: which organisation must deploy information security governance, why the organisation should concern itself with this discipline, how the organisation should go about implementing information security governance, and what consequences will ensue if the organisation fails to comply with this discipline, are in dispute. Uncertainty surrounding the answers to these questions contribute to the reluctance and skepticism with which this discipline is approached. This dissertation evolves around the legal implications of information security governance by establishing who is responsible for ensuring compliance with this discipline, illustrating the value to be derived from information security governance, the methodology of applying information security governance, and liability for non-compliance with this discipline, ultimately providing the reader with certainty and clarity regarding the above mentioned questions, while simultaneously enabling the reader to gain a better understanding and appreciation for the discipline information security governance. The discussion hereafter provides those who should be concerned with information security governance with practical, pragmatic advice and recommendations on: (i) The legal obligation to apply information security; (ii) Liability for failed information security; (iii) Guidelines on how to implement information security; and (iv) A due diligence assessment model against which those responsible for the governance and management of the organisation may benchmark their information security efforts.