<p>The heuristic methods used by the anti-trojan application TrojanHunter have been evaluated. The evaluation shows that the heuristic scan engine of TrojanHunter has a very good detection ratio and that the detection ratio can be even further improved by implementing the suggested improvements, the most important of which is a white list to avoid misidentifying files that are known not to be trojans.</p>

<p>Att utveckla, tillvarata och återanvända kunskap är centrala företeelser för organisationers framåtskridande och utveckling. Härmed har kunskapsmanagement (KM) en viktig roll för och i organisationer. Med KM eftersträvas bl a att medvetandegöra medarbetarnas kunskaper i syfte att hantera, utveckla och sprida dem på ett för organisationen fruktbart sätt. Genom en framgångsrik KM finns potential att öka organisationers handlingsförmåga, följaktligen även verksamheters värdeskapande och konkurrenskraft. Icke desto mindre är kunskap en abstrakt och svårhanterlig organisatorisk tillgång. Därtill, trots att det finns en hel del skrivet kring KM, kan det vara svårt för organisationer att förstå hur de praktiskt ska arbeta med detta verksamhetsområde, samt vad det innebär.</p><p>I syfte att öka förståelsen för KM har jag studerat och kritiskt analyserat en del existerande litteratur kring området. Med analysen som utgångspunkt har ett antal forskningsfrågor preciserats. För att överbrygga en del av de oklarheter som identifierats i samband med litteraturgenomgången, samt för att svara på avhandlingens forskningsfrågor, har stöd sökts i andra teorier, bl a kunskapsteori och teori om hur vi kan se på verksamheter. Därtill har hanteringen av och synen på kunskap studerats genom en fallstudie genomförd på ett konsultbolag inom IT-branschen. Utifrån litteraturanalysen, grundning i annan teori, samt avhandlingens empiriska data har jag presenterat min syn på organisationers kunskapsverksamheter (min benämning på kunskapsmanagement).</p><p>Resultatet av avhandlingsarbetet är bl a en utvecklad och preciserad begreppsapparat för organisatorisk kunskapsverksamhet (KM). Detta innefattar bl a en klassificering av begreppet organisatorisk kunskap och dess relation till organisatorisk handling. I avhandlingen klassificeras även ett antal vanliga situationer för kunskapande (lärande), vilka i sin tur relateras till organisationers kärnverksamhet respektive kunskapsverksamhet. Ett av huvudbidragen är en modell över organisatoriskt kunskapsverksamhet. Modellen inkluderar kunskapsverksamhetens centrala förutsättningar, handlingar, resultat, samt dess relation till kärnverksamheten. Genom denna avhandling vill jag bidra med en ökad förståelse för vad kunskapsverksamheter handlar om och vad som behöver beaktas för att utveckla en framgångsrik kunskapsverksamhet.</p>

<p>This dissertation examines Information and Communication Technology (ICT) use in workplace environments in Norway and the United States. Despite the appropriateness and timeliness of the World Wide Web and Internet as topics of study today, little is known about how people actually use a full range ICTs in naturalistic settings. This investigation primarily addresses the following research question: <i>How do workers use ICTs to meet business objectives when a full array of ICTs is available to them</i>? The data, targeting high-end ICT users, was collected over a two-year period, from Fall 2000 through Fall 2002. During this time, 72 semi-structured, in-depth individual interviews—36 in the U.S. and 36 in Norway—were collected. A Grounded Theory approach was chosen for its ability to generate descriptive and explanatory accounts of contemporary organizational ICT-use behavior by advanced users. Our analysis resulted in four papers:</p><p>Paper One</p><p>The Reflexivity Between ICTs and Business Culture: Using Hofstede’s Theory to Compare Norway and the United States.</p><p>● The data of advanced ICT users were coded, analyzed, and placed into Hofstede’s (1980) four-dimensional framework of national-culture</p><p>differences (power distance, uncertainty avoidance, individualism, and masculinity). We proposed that ICT-use comparisons between the two countries support Hofstede’s findings. We found only partial support for these propositions. As expected, Norway and the U.S. are similar on two dimensions (power distance and uncertainty avoidance), but contrary to expectations, they are also similar on the two dimensions where we expected differences (individualism and masculinity).</p><p>Paper Two</p><p>Social Actors’ Enactment of Media Use and Organizational Environments</p><p>● This paper uses the concept of scripts to couple Weick’s (1979) notion of enactment and Langer’s (2000) theory of mindfulness/mindlessness with empirical data on the use of ICTs in organizations. The findings: (1) show that the notion of clear-cut boundaries between an organization and its “environment” is problematic, and illustrate how organizational members indeed enact—or co-create—the environments of their organizations; (2) validate that mindfulness is required for media richness theory to be predictive; and (3) illustrate how organizational members construct the richness of one medium through the use of other media.</p><p>Paper Three</p><p>A Reflexive Model of ICT Practices in Norway and the United States</p><p>● Using Grounded Theory as a research method, and Adaptive Structuration Theory (AST) as our conceptual basis, this paper proposes an empirical model of ICT use. The model consists of four core categories: satisficing, channels, communication structure, and environmental agents. The model lays out the factors that influence individuals’ use when they choose various ICTs. Findings suggest that: (1) the parts of the model are interdependent and mutually causal in that individuals consider and even reconsider the use of multiple communication channels within and between tasks, (2) there are contradictions in how ICTs are perceived with respect to credibility, and (3) people will perceive the utility of ICTs differently depending on the nature of the task and the meta-message that using these sources may convey to others.</p><p>Paper Four</p><p>The Study of Sequence: A Narrative Analysis of ICT Practices</p><p>● This paper examines how—and why—ICT use-sequences vary. Building on an earlier context-based model of ICT use (Paper Three), we analyzed interviews with experienced users to learn the reasons for their sequences. The paper extends these individual strategies and the ICT model presented in Paper Three by displaying 24 different sequences possible from the four categories of the model. The effect of examining these different possible sequences is their equi-finality. That is, all iterations of sequence lead to ideal and equally successful outcomes. </p><p>The contributions to theory and practice that can be drawn from these four papers follow three main themes: (1) how workers use multiple ICT, often in a sequential manner, when solving tasks, (2) how workers often satisfice when making choices about what ICTs to use, and (3) how a dynamic and reflexive relationship between users, organizations, and ICTs (social construction) shape how individuals use ICTs. These contributions fill several current theoretical gaps and add to our current practical understanding of ICT use behavior. Communication in organizations has changed drastically as a result of the use of ICTs over the last dozen years. This study maps some particulars of these changes; as the core of my research program, I plan to continue studying these dynamics.</p>

<p>Proxies, software deployed inside the network, play a fundamental role in the Internet by providing enhanced functionality to the network. Deployment of proxies is a flexible way of extending the Internet architecture with new services and to cope with problems that were not foreseen at the time the original Internet protocols were defined. The creation of the Internet is an enormous investment in time, effort and money, and proxies allow us to build on the existing infrastructure to enhance its functionality, rather than replace it.</p><p>As the use of proxies increase, so does the problem of proxy configuration and deployment, especially with respect to interference between different proxies. With a limited number of different proxies, this problem can be dealt with manually, or by encoding knowledge of interfering proxies into each proxy. As the number of proxies grow, methods to automatically detect and cope with conflicts must be devised.</p><p>Therefore, proxies need to coordinate with each other. Towards this end, a signalling protocol that can be used to establish and configure a sequence of one or more proxies along an end-to-end flow is proposed. The protocol is realized as an extension of IP, using an IP option, which simplifies its deployment in the Internet.</p><p>In order to facilitate reasoning about coordination, conflicts and deployment of proxies, a model has been developed. The model is based on the concept of regions, also developed in the thesis. Regions are interconnected parts of the network that share a common property, e.g. administrative control or error characteristic. Along with the model, a classification of proxy architectures with respect to how they gather information and deploy proxies is presented. A method based on this model is also proposed.</p><p>We also propose an algorithm for controlling compression to maximize perceived throughput in situations where available bandwidth and CPU power varies. Along with the algorithm, experimental results that show that the algorithm approximates the best non-adaptive choice in a number of situations are presented. This algorithm has been implemented as an end-to-end enhancement.</p>

This dissertation examines Information and Communication Technology (ICT) use in workplace environments in Norway and the United States. Despite the appropriateness and timeliness of the World Wide Web and Internet as topics of study today, little is known about how people actually use a full range ICTs in naturalistic settings. This investigation primarily addresses the following research question: How do workers use ICTs to meet business objectives when a full array of ICTs is available to them? The data, targeting high-end ICT users, was collected over a two-year period, from Fall 2000 through Fall 2002. During this time, 72 semi-structured, in-depth individual interviews—36 in the U.S. and 36 in Norway—were collected. A Grounded Theory approach was chosen for its ability to generate descriptive and explanatory accounts of contemporary organizational ICT-use behavior by advanced users. Our analysis resulted in four papers: Paper One The Reflexivity Between ICTs and Business Culture: Using Hofstede’s Theory to Compare Norway and the United States. ● The data of advanced ICT users were coded, analyzed, and placed into Hofstede’s (1980) four-dimensional framework of national-culture differences (power distance, uncertainty avoidance, individualism, and masculinity). We proposed that ICT-use comparisons between the two countries support Hofstede’s findings. We found only partial support for these propositions. As expected, Norway and the U.S. are similar on two dimensions (power distance and uncertainty avoidance), but contrary to expectations, they are also similar on the two dimensions where we expected differences (individualism and masculinity). Paper Two Social Actors’ Enactment of Media Use and Organizational Environments ● This paper uses the concept of scripts to couple Weick’s (1979) notion of enactment and Langer’s (2000) theory of mindfulness/mindlessness with empirical data on the use of ICTs in organizations. The findings: (1) show that the notion of clear-cut boundaries between an organization and its “environment” is problematic, and illustrate how organizational members indeed enact—or co-create—the environments of their organizations; (2) validate that mindfulness is required for media richness theory to be predictive; and (3) illustrate how organizational members construct the richness of one medium through the use of other media. Paper Three A Reflexive Model of ICT Practices in Norway and the United States ● Using Grounded Theory as a research method, and Adaptive Structuration Theory (AST) as our conceptual basis, this paper proposes an empirical model of ICT use. The model consists of four core categories: satisficing, channels, communication structure, and environmental agents. The model lays out the factors that influence individuals’ use when they choose various ICTs. Findings suggest that: (1) the parts of the model are interdependent and mutually causal in that individuals consider and even reconsider the use of multiple communication channels within and between tasks, (2) there are contradictions in how ICTs are perceived with respect to credibility, and (3) people will perceive the utility of ICTs differently depending on the nature of the task and the meta-message that using these sources may convey to others. Paper Four The Study of Sequence: A Narrative Analysis of ICT Practices ● This paper examines how—and why—ICT use-sequences vary. Building on an earlier context-based model of ICT use (Paper Three), we analyzed interviews with experienced users to learn the reasons for their sequences. The paper extends these individual strategies and the ICT model presented in Paper Three by displaying 24 different sequences possible from the four categories of the model. The effect of examining these different possible sequences is their equi-finality. That is, all iterations of sequence lead to ideal and equally successful outcomes. The contributions to theory and practice that can be drawn from these four papers follow three main themes: (1) how workers use multiple ICT, often in a sequential manner, when solving tasks, (2) how workers often satisfice when making choices about what ICTs to use, and (3) how a dynamic and reflexive relationship between users, organizations, and ICTs (social construction) shape how individuals use ICTs. These contributions fill several current theoretical gaps and add to our current practical understanding of ICT use behavior. Communication in organizations has changed drastically as a result of the use of ICTs over the last dozen years. This study maps some particulars of these changes; as the core of my research program, I plan to continue studying these dynamics.

När ett system införs, spelar det ingen roll hur god funktionalitet det har, om användarna av någon anledning inte kan eller vill använda det på ett effektivt sätt. I första hand bestäms användbarheten hos ett program av egenskaper hos detta och hos de aktuella användarna. God användbarhet beror av acceptans från användarna, kompetens hos användarna och användarvänlighet hos systemet. För att undersöka hur man kan uppnå hög användbarhet och därmed en hög grad av användande vid införande av ett nytt system, har vi gjort en undersökning av användbarheten och användandet av ett system vid Landstinget i Östergötland. Våra slutsatser visar på att utbildning och information är mycket viktiga faktorer för att uppnå hög användbarhet för ett system. Många har en motvilja mot att använda datorer och problem med att se vilka fördelar ett införande av ett nytt system kan medföra, något vi anser kan lösas med bättre utbildning och information. Trots att teorier om användbarhet funnits i över tio år, har vi funnit att det forfarande inte tas tillräcklig hänsyn till de grundläggande faktorer som påverkar användbarheten vid införande av ett system.

<p>The objective with this thesis is to describe security mechanisms that are inte-grated or are proposed to be integrated with the Session Initiation Protocol (SIP). SIP is used for establishing, modifying, and terminating multimedia ses-sions over the IP network. This thesis is divided into two main parts, where the first part describes the implemented security mechanisms in SIP and the second part describes a number of proposed security mechanisms that may be implemented in SIP. At the end of the report there is a section that presents the scripts and results from different security tests that were performed on two implementations of SIP. Apart from describing different security mechanisms in the first part of this thesis, this section also contains an analysis on how possible security threats against SIP may be used to launch different attacks. The analysis also describes how these attacks may be prevented, if possible, by using the secu-rity mechanisms provided by SIP. The second part also contains an analysis section, which is focusing on finding the advantages and disadvantages of using a specific security mechanism compared to a similar security mechanism that is currently used or has been used in SIP. In the last section of this thesis I present my conclusions and a summary of the results.</p>

<p>One important issue faced by companies is to secure their information and resources from intrusions. For accessing a resource almost every system uses the approach of assigning a unique username and a password to all legitimate users. This approach has a major drawback. If an intruder gets the above information then he can become a big threat for the company and its resources. To strengthen the computer security there are several biometric methods for identity verification which are based on the human body’s unique characteristics and behavior including fingerprints, face recognition, retina scan and signatures. However most of these techniques are expensive and requires the installation of additional hardware. </p><p>This thesis focuses on keystroke dynamics as an identity verifier, which are based on the user’s unique habitual typing rhythm. This technique is not just looking for <i>what</i> the user types but also <i>how</i> he types. This method does not require additional hardware to be installed and are therefore rather inexpensive to implement. This thesis will discuss how identity verification through keystroke characteristics can be made, what have been done in this area and give advantages and disadvantages of the technique.</p>

<p>The company Roxen Internet Software have an implementation of the secure network protocol SSL (Secure Sockets Layer) which is used in their web server product. This report describes the upgrading of that implementation to the TLS1.0 (Transport Layer Security) standard. It also describes a performance investigation of the SSL/TLS support in the Roxen WebServer and compares it with other common web servers. The initial setup time for the secure SSL/TLS connection was found to be very long in the Roxen Webserver compared to its competitors. The main bottleneck, in the Roxen implementation, was found to be the modular exponentiation that is the core of the RSA decryption algorithm. One suggested improvement is to upgrade the bignumber numerical package used in Roxen WebServer, GMP (The GNU Multiple Precision arithmetic library) from version 2.0 to version 4.0. The newer version of the bignumber package have been measured to have considerably better performance in its modular exponentation operation.</p>

<p>Software Defined Radios (SDRs) are redefining the current landscape of wireless communications in both military and commercial sectors. The rapidly evolving capabilities of digital electronics are making it possible to execute significant amounts of signal processing on general purpose processors ratherthan using special-purpose hardware.</p><p>As a consequence of the availability of SDR, applications can be used to implement flexible communication systems in an operating prototype within a very short time. However, the initial lack of standards and design rules leads to incompatibility problems when using products from different manufacturers. This problem is critical for the military and public safety sectors, for this reason the US Army was interested in SDR and carried out research into the specification of a common software infrastructure for SDR. This initiative started in the mid-1990s and evolved into the Software Communications Architecture (SCA).</p><p>SCA is a non-proprietary, open architecture framework that allows a designer to design interoperable and platform independent SDR applications. At the same time the SCA framework, by abstracting the radio communication system, speeds up waveform development because developers no longer have to worry about hardware details.</p><p>This thesis project uses OSSIE, an open source SCA implementation, to illustrate the process of developing a waveform. Today companies are exploiting open source solutions and investing money to evaluate and improve available technologies rather than developing their own solutions: OSSIE provides a working SCA framework without any license cost. OSSIE also provides some tools to develop SCA waveforms. Of course open source software comes with some limitations that a designer must take into account. Some of these limitations will be described for OSSIE (specifically the limited documentation and lack of libraries), along with some suggestions for how to reduce their impact.</p><p>This thesis project shows in detail the development process for SCA waveforms in OSSIE. These details are examined in the course of successfully implementing a target waveform to enable the reader to understand the advantagies and disadvantages of this technology and to facilitate more people using OSSIE to develop waveforms. Although a waveform was successfully implemented there were unexpected issues with regard to the actual behavior of the waveform when implemented on the hardware used for testing.</p> / QC 20100831