Nearly all present-day commercial intrusion detection systems are based on a hierarchical architecture. In such an architecture, the root node is responsible for detecting intrusions and for issuing responses. However, an intrusion detection system (IDS) based on a hierarchical architecture has many single points of failure. For example, by disabling the root node, the intrusion-detection function of the IDS will also be disabled. To solve this problem, an IDS inspired by the human immune system is proposed. The proposed IDS has no single component that is responsible for detecting intrusions. Instead, the intrusion-detection function is divided and placed within mobile agents. Mobile agents act similarly to white blood cells of the human immune system and travel from host to host in the network to detect intrusions. The IDS is fault-tolerant because it can continue to detect intrusions even when most of its components have been disabled. / Computer Science (School of Computing) / M. Sc. (Computer Science)

The availability of numerous mobile agent systems with its own strengths and weaknesses poses a problem when deciding on a particular mobile agent system. In this dissertation, factors based on mobility, communication and security of the mobile agent systems are presented and used as a means to address this problem. To facilitate in the process of selection, a grouping scheme of the agent system was proposed. Based on this grouping scheme, mobile agent systems with common properties are grouped together and analyzed against the above-mentioned factors. In addition, an application was developed using the Aglet Software Development Toolkit to demonstrate certain features of agent mobility, communication and security. / Theoretical Computing / M. Sc. (Computer Science)

The South African mining industry has not been shielded from the criminal threat the country faces. In this case study, the nature and extent of asset theft at one of the largest mining companies in South Africa is analysed. The crime prevention strategy adopted by the mine to curb asset theft was studied over a period of five years. This involved a survey of the views of the security managers on the effectiveness of the strategy implemented by the mine. Against the background of the South African Government’s broad description of the crime prevention approach adopted by the country, the researcher explored whether it would be practicable to implement an integrated crime prevention strategy – encompassing situational, social and law enforcement crime prevention approaches on primary, secondary and tertiary level – at the participating mine in order to curb asset theft. / Police Practice / M. Tech. (Policing)

Incidents, threats and vulnerabilities have the potential to negatively affect an organisation’s assets. Information on these incidents, threats and vulnerabilities are important to security. It is therefore necessary for this security information to be effectively and efficiently managed, so that correct decisions may be made on the implementation of security risk control measures. This study explored the management of security information in the security industry by undertaking the following: • establishing the “status quo” of the collection and analysis of security information and the implementation of security risk control measures in practice; • identifying the nature and extent of problems experienced in the collection and analysis of security information and the implementation of security risk control measures; and the • discovery of a new Security Information Management Model (SIMM). Mixed methods research was used to study the management of security information in the security industry. The explorative research design was used for this purpose. Semi-structured and focus group interviews were conducted with senior security managers and operational security officers, respectively. The grounded theory research design was used to analyse the qualitative data in order to generate a substantive grounded theory. The theory is that security officers operate without a standardised framework to manage security information. The data from the semi-structured and the focus group interviews were used to design a questionnaire to conduct a survey using the quantitative approach. The non-experimental research design was used to conduct this self-administered questionnaire survey. The data from this questionnaire survey helped validate and confirm the substantive grounded theory. The study found that there was the need for a Security Information Management Model to manage security information in the security industry. Based on this finding the researcher recommended a new Security Information Management Model for the management of security information in the security industry. / Criminology / D. Litt. et Phil. (Criminology)

The problem encountered by the researcher was that the South African Police Service Cyber-Crimes Unit is experiencing problems in seizing computer evidence. The following problems were identified by the researcher in practice: evidence is destroyed or lost because of mishandling by investigators; computer evidence is often not obtained or recognised, due to a lack of knowledge and skills on the part of investigators to properly seize computer evidence; difficulties to establish authenticity and initiate a chain of custody for the seized evidence; current training that is offered is unable to cover critical steps in the performance of seizing computer evidence; computer seizure as a technique requires specialised knowledge and continuous training, because the information technology industry is an ever-changing area. An empirical research design, followed by a qualitative research approach, allowed the researcher to also obtain information from practice. A thorough literature study, complemented by interviews, was done to collect the required data for the research. Members of the South African Police Cyber-crime Unit and prosecutors dealing with cyber-crime cases were interviewed to obtain their input into, and experiences on, the topic. The aim of the study was to explore the role of computers in the forensic investigation process, and to determine how computers can be seized without compromising evidence. The study therefore also aimed at creating an understanding and awareness about the slippery nature of computer evidence, and how it can find its way to the court of law without being compromised. The research has revealed that computer crime is different from common law or traditional crimes. It is complicated, and therefore only skilled and qualified forensic experts should be used to seize computer evidence, to ensure that the evidence is not compromised. Training of cyber-crime technicians has to be priority, in order to be successful in seizing computers. / Department of Criminology / M.Tech. (Forensic Investigation)

Thesis (MComm (Business Management))--Stellenbosch University, 2008. / The market share of online purchasing is under two percent of total retail spending, which provides an indication that consumers have been slow to adopt online purchasing. Previous research has shown that consumers perceive risks associated with purchasing online and these perceptions are likely to affect purchase intention. Little research, however, has been done on perceived risk relating specifically to online purchasing, and in particular, risk related to branded and non-branded retailer websites. Research has shown that brand knowledge has a direct effect on a consumer’s intention to purchase from an online retailer and that this relationship between brand knowledge and intent to purchase online is mediated by perceived risk. The purpose of this exploratory study was therefore to investigate the consumer-perceived risks associated with the intention to purchase online. The research problem considered the question whether the perceived risks (financial, performance, physical, time, social and psychological risks) associated with a branded website (Kalahari.net) are different from the perceived risks associated with a non-branded website (Books.com). It was found that four types of perceived risk exist namely, performance, time, social, and personal risk. Of these risks, only performance risk had an influence on a consumer’s purchase intention from a non-branded website whereas performance and personal risk influenced a consumer’s intention to purchase from a branded website. It was also revealed that consumers perceive performance, time, and social risk as not statistically different when purchasing from a non-branded or a branded website. However, personal risk was perceived to be statistically differently for the two websites. In addition, the brand image dimension of brand knowledge had an influence on a consumer’s purchase intention from both the branded and non-branded websites. The brand awareness dimension of brand knowledge did not influence purchase intention at all. For all four risk types on both the branded and nonbranded websites (except social risk on Books.com), at least one and in some cases, both dimensions of brand knowledge influenced the degree of perceived risk associated with purchasing on the particular website. Finally, it was concluded that the more information search a consumer does before purchase of a book on a branded or non-branded website, the higher their perceived risk associated with purchasing from the particular website. A number of recommendations were made. Methods for decreasing the amount of performance risk which consumers perceive when purchasing a book online were firstly suggested. It was further recommended that Kalahari.net investigate the dimensions of their brand such as brand image, brand awareness, and brand trust, to identify the reasons why consumers perceive performance, social and time risk as being not statistically different when purchasing on a branded and a non-branded website. Since consumers did not see a difference between the brand image of the branded and the non-branded websites, it was recommended that the branded website make every effort to investigate their current branding strategy to identify the reasons consumers view the branded website in the same manner as the non-branded website. Furthermore, since both dimensions of brand knowledge influenced the degree of perceived risk associated with purchasing on the particular website to a certain extent, it was recommended that online retailers focus on building familiarity, positive thoughts, feelings, associations, and beliefs concerning the online retailer brand. Finally, it was recommended that the influence of information search online on perceived risk associated with purchasing be further investigated; because this study found that an action that was traditionally initiated as a means for decreasing perceived risk can now be attributed to increased consumer-perceived risk associated with online shopping.

Thesis (LLM)--Stellenbosch University, 2004 / ENGLISH ABSTRACT: This thesis deals with the criminal liability of Internet providers. The focus is on Germany, but the analysis is put in a wider, comparative context. This is done with reference to South Africa, as well as Europe and the American system. This thesis demonstrates and discusses the existing legal norms to regulate Internet provider liability for illegal content on the Internet and the international efforts to deal with this issue. In the introduction it is shown how the Internet has given rise to a new form of global communication and the accompanying legal problems. This is followed by an examination of the different functions Internet providers have. A survey of some of the important crimes affecting the Internet and also some Internet-specific offences put the more general issue of liability in a more specific context. Traditional and new forms of crimes are discussed. This section is followed by an analysis of Internet provider liability under German criminal law and Germany's Teleservices Act. From an international criminal law perspective some international instruments, like the Cybercrime Convention of the Council of Europe, is discussed. National legislation, especially in the context of the European Union, must always be put in the proper regional and international context. The thesis concludes with some thoughts on alternative, or perhaps complementary, methods to fight illegal and criminal conduct on the Internet. This is done not as a critique of the responses to Internet crime, but rather to strengthen the many hands trying to reduce Internet crime. / AFRIKAANSE OPSOMMING: Hierdie tesis handeloor die strafregtelike aanspreekliheid van Internet diensverskaffers. Die fokus val op Duitsland, maar die analise word ook geplaas in 'n wyer, vergelykende konteks. Dit word gedoen met verwysing na Suid-Afrika, sowel as Europa en die VSA. Die tesis demonstreer en bespreek die bestaande regsnorme wat Internet diensverskaffers reguleer met spesifieke verwysing na aanspreeklikheid vir onwettige inhoud op die Internet en internasionale pogings om hierdie probleem aan te spreek. Ter inleiding word daar aangetoon hoe die Internet aanleiding gee tot nuwe vorme van globale kommunikasie en die regsprobleme wat dit tot gevolg het. Dit word gevolg deur 'n ondersoek na die verskillende funksies van Internet verskaffers. 'n Ontleding en bespreking van Internet-spesifieke misdrywe plaas die meer algemene vraagstuk in 'n meer gefokusde konteks. Tradisionele en nuwe vorme van misdaad word bespreek. Hierdie afdeling word gevolg deur 'n ontleding van Internet diensverskaffer aanspreeklikheid ingevolge Duitse reg en die Duitse wetgewing op die terrein van telediens. Uit 'n internasionale strafreg oogpunt word sekere internasionale instrumente, soos die Cybercrime Convention van die Raad van Europa, bespreek. Nasionale wetgewing, veral in die konteks van die Europese Unie, word ook in die relevante regionale en internasionale konteks geplaas. Die tesis word afgesluit met sekere gedagtes oor alternatiewe, of moontlik komplimentêre, metodes in die stryd teen Internet-kriminaliteit. Dit moet nie gesien word as kritiek op die huidige stand van sake nie, maar eerder as 'n poging om die talle rolspelers in die stryd teen Internet misdaad se hande te sterk.

This work presents the development of the Statistical Location-Assisted Broadcast (SLAB) protocol, a multi-hop wireless broadcast protocol designed for vehicular ad-hoc networking (VANET). Vehicular networking is an important emerging application of wireless communications. Data dissemination applications using VANET promote the ability for vehicles to share information with each other and the wide-area network with the goal of improving navigation, fuel consumption, public safety, and entertainment. A critical component of these data dissemination schemes is the multi-hop wireless broadcast protocol. Multi-hop broadcast protocols for these schemes must reliably deliver broadcast packets to vehicles in a geographically bounded region while consuming as little wireless bandwidth as possible. This work contains substantial research results related to development of multi-hop broadcast protocols for VANET, culminating in the design of SLAB. Many preliminary research and development efforts have been required to arrive at SLAB. First, a high-level wireless broadcast simulation tool called WiBDAT is developed. Next, a manual optimization procedure is proposed to create efficient threshold functions for statistical broadcast protocols. This procedure is then employed to design the Distribution-Adaptive Distance with Channel Quality (DADCQ) broadcast protocol, a preliminary cousin of SLAB. DADCQ is highly adaptive to node density, node spatial distribution pattern, and wireless channel quality in realistic VANET scenarios. However, the manual design process used to create DADCQ has a few deficiencies. In response to these problems, an automated design procedure is created that uses a black-box global optimization algorithm to search for efficient threshold functions that are evaluated using WiBDAT. SLAB is finally designed using this procedure. / Expansive simulation results are presented comparing the performance of SLAB to two well-published VANET broadcast protocols, p -persistence and Advanced Adaptive Gossip (AAG), and to DADCQ. The four protocols are evaluated under varying node density and speed on five different road topologies with varying wireless channel fading conditions. The results demonstrate that unlike p-persistence and AAG, SLAB performs well across a very broad range of environmental conditions. Compared to its cousin protocol DADCQ, SLAB achieves similar reachability while using around 30% less wireless bandwidth, highlighting the improvement in the automated design methodology over the manual design. / by Michael J. Slavik. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 200?. Mode of access: World Wide Web.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-05-04T13:39:33Z No. of bitstreams: 1 Michele Cia.pdf: 2227086 bytes, checksum: 76f6484ba46ba455d6ea486c9028a25e (MD5) / Made available in DSpace on 2018-05-04T13:39:33Z (GMT). No. of bitstreams: 1 Michele Cia.pdf: 2227086 bytes, checksum: 76f6484ba46ba455d6ea486c9028a25e (MD5) Previous issue date: 2018-03-16 / The present paper, using the hypothetical-deductive method, tested the hypothesis that requiring an individual to no longer be considered a risk to society in order to suspend the execution of a safety measure is inadequate, since paragraph 1 of article 97 of the penal code is not compatible with the constitution. In order to try to defeat this hypothesis, the emergence of the concept of dangerousness was analyzed, within the scope of criminological positivism; the concepts of abnormality and pathology and their relationship to dangerousness were investigated in a Foucaultian perspective; the psychiatric concept of dangerousness was examined; the (in)existence of free will and its relationship with the dangerous category was analyzed; the use of the dangerous category by National Socialism was examined; the concept of dangerousness was analyzed critically, in the scope of legal-penal dogmatism; the purpose of safety measures and requiring the individual to no longer be considered a risk to society in order to suspend the execution of a safety measure were analyzed; the foundations of the Federative Republic of Brazil, constitutional principles of criminal law and individual guarantees, as well as the rights of persons with mental health disorders in the domestic legal system and in international human rights treaties were studied at length; the practical purposes of safety measures and the operability of the dangerous category in its` legitimization were examined. The hypothesis proved to be true, resulting in the recognition of the illegitimacy of the dangerous category in the Brazilian legal system and, consequently, of the safety measures. The paper proposes a legislative amendment in the sense of the impossibility of recognizing the exclusion of imputability due to psychological anomalities and the end of the dualism of criminal sanctions / A presente pesquisa, através do método hipotético-dedutivo, testou a hipótese de que é inadequada a exigência da cessação da periculosidade como requisito para o fim da execução da medida de segurança, não tendo sido recepcionado pela Constituição Federal o dispositivo presente no § 1º do art. 97 do Código Penal. Para tentar falsear a hipótese, analisou-se o surgimento do conceito de periculosidade, no âmbito do positivismo criminológico; investigou-se os conceitos de anormalidade e de patologia e sua relação com a periculosidade, em uma perspectiva foucaultiana; perscrutou-se a psiquiatrização do conceito de periculosidade; analisou-se a (in)existência do livre-arbítrio e sua relação com a categoria da periculosidade; examinou-se a utilização da categoria da periculosidade pelo nacional-socialismo; analisou-se criticamente o conceito de periculosidade, no âmbito da dogmática jurídico-penal; analisou-se as finalidades da medida de segurança, e sua compatibilidade com a exigência da cessação da periculosidade como requisito para o fim da execução da medida de segurança; estudou-se detidamente os fundamentos da República Federativa do Brasil, os princípios constitucionais penais e as garantias individuais, assim como os direitos dos portadores de transtornos mentais no ordenamento jurídico interno e nos tratados internacionais de direitos humanos; e investigaram-se as finalidades práticas da medida de segurança e a operacionalidade da categoria da periculosidade em sua legitimação. A hipótese mostrou-se verdadeira, o que redundou no reconhecimento da ilegitimidade da categoria da periculosidade no ordenamento jurídico brasileiro e, em consequência, da própria medida de segurança. A pesquisa propõe alteração legislativa no sentido da impossibilidade de reconhecimento de inimputabilidade em razão de anomalia psíquica.e do fim do dualismo das sanções penais

Dans cette thèse, nous questionnons l’impact du terrorisme international et des mesures de sûreté sur le comportement des usagers du réseau de transport aérien mondial. A l’aide d’un modèle économétrique, nous analysons une base de données inédite, AirNetTerror, composée de l’ensemble des vols internationaux à destination des Etats-Unis de 1990 à 2006, et des données du terrorisme international par pays sur cette période. La pertinence de notre travail est double. D’une part, nos interrogations sur les comportements des voyageurs et leurs éventuelles substitutions d’itinéraires en lien avec le terrorisme international n’ont, à notre connaissance, jamais été traitées. D’autre part, en abordant le transport aérien sous l’angle du réseau, nous proposons une vision dynamique des répercussions des comportements des usagers en lien avec la menace terroriste et les mesures de sûreté. En particulier, la prise en compte de la situation de sûreté interdépendante régissant le réseau aérien mondial nous permet de questionner l’existence de failles dans les mesures de sûreté. Nos résultats soulignent l’impact avéré et significatif des événements du terrorisme international, mais aussi des mesures de sûreté sur le réseau de transport aérien mondial. De plus, nous observons localement des substitutions d’itinéraires des voyageurs aériens en lien avec ces phénomènes. Ainsi, l’effet combiné de la menace terroriste internationale et des mesures de sûreté semble être à l’origine de ruptures d’équilibre, certes limitées mais réelles, des flux de passagers du réseau de transport aérien mondial. Notre thèse, parce qu’elle place le comportement du voyageur au centre des interactions stratégiques entre les acteurs de la sûreté et les terroristes, permet d’apporter une vision inédite de l’impact du terrorisme international sur le transport aérien. / In our dissertation, we question the impact of both international terrorism and security measures on the behavior of the users of the global air transportation network. Using an econometric model, we analyze a new database, AirNetTerror, which contains data on all international passenger flows toward the U.S. from 1990 to 2006 as well as the events of international terrorism by country for the same period. The relevance of our research is twofold. On the one hand, our investigation regarding air travelers’ behavior and their possibilities of modifying their itinerary in light of international terrorism has – so far as we know – never been studied. On the other hand, as we analyze passenger flows from the perspective of the network, we propose a dynamic representation of the impact of travelers’ behavior changes related to terrorist threats and security measures. In particular, taking into account the interdependent security that rules the global air transport network, allows us to question the existence of failures in security measures. Our results underline a significant impact of both international terrorist events and security measures. Furthermore, we locally observe itinerary modifications of travelers that are linked to the previous phenomena. Thus, the combined effect of terrorist threats and security measures seems to lead to equilibrium breaks – that are limited but real – in passenger flows of the global air network. Our thesis offers a different representation of the impact of international terrorism on air transport by placing the traveler’s behavior at the center of the strategic interactions between security actors and terrorists.