| 1. |
- Ciszkowski, Tomasz, et al.
(författare)
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SecMon : end-to-end quality and security monitoring system
- 2008
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Ingår i: Annales UMCS Informatica. - : Uniwersytet Marii Curie-Sklodowskiej. - 1732-1360 .- 2083-3628. ; AI 8:1, s. 185-201
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Tidskriftsartikel (refereegranskat)abstract
- The Voice over Internet Protocol (VoIP) is becoming a more available and popular way of communication for the Internet users. This also applies to the Peer-to-Peer (P2P) systems and merging these two have already proven to be successful (e.g. Skype). Even the existing standards of VoIP provide an assurance of security and Quality of Service (QoS), however, these features are usually optional and supported by a limited number of implementations. As a result, the lack of mandatory and widely applicable QoS and security guaranties makes the contemporary VoIP (P2P VoIP systems even more so than client-server ones) systems vulnerable to attacks and network disturbances. In this paper we are facing these issues and propose the SecMon system, which simultaneously provides a lightweight security mechanism and improves quality parameters of the call. SecMon is intended specially for VoIP service over P2P networks and its main advantage is that it provides authentication, data integrity services, adaptive QoS and (D)DoS attacks detection. Moreover, the SecMon approach represents a low-bandwidth consumption solution that is transparent to the users and possesses a self-organizing capability. The above- mentioned features are accomplished mainly by utilizing two information hiding techniques: digital audio watermarking and network steganography. These techniques are used to create covert channels that serve as transport channels for lightweight QoS measurement’s results. Furthermore, these metrics are aggregated in a reputation system that is used for the best route path selection in the P2P network. The reputation system also helps to mitigate (D)DoS attacks, maximize performance and increase transmission efficiency in the network.
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| 2. |
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| 3. |
- Eliasson, Charlott, et al.
(författare)
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A criteria-based evaluation framework for authentication schemes in IMS
- 2009
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Konferensbidrag (refereegranskat)abstract
- The IP Multimedia Subsystem (IMS) is regarded as one of the most prominent enablers for successful service provisioning across different access network technologies and devices. While new paradigms, e.g. seamless communication, enter the IMS, existing solutions, e.g. for authentication, need to be redefined, which is one of the major activities within the EUREKA!-funded Mobicome project, involving operators, manufacturers and academia. As there exist several candidate solutions for providing seamless authentication, there is a need for a set of criteria that helps to select the candidate that fulfils those criteria in a bestpossible way. Given this background, this position paper proposes a framework of criteria for the evaluation of authentication schemes in IMS. The primary criteria are security, user-friendliness and simplicity. Inbetween these criteria, the secondary criteria can be found. These are awareness, usability and algorithms. Each criterion, both primary and secondary, is then also divided into one or several substantiating sub-criteria. The discussion of the criteria is followed by a description of the evaluation methodology, which comprises both qualitative and quantitative evaluations such as SWOT analysis, use of NIST and ISO guidelines, user rankings, and measurements of authentication times. The paper is concluded with an outlook on future work, including studies and experiments.
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| 4. |
- Eliasson, Charlott, et al.
(författare)
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An Electronic Voting System Supporting Vote Weights
- 2006
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Ingår i: Internet Research. - Paphos, Cyprus : Emerald Group Publishing Limited. - 1066-2243. ; 16:5, s. 507-518
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Tidskriftsartikel (refereegranskat)abstract
- Purpose – This paper aims to provide a solution for allowing an arbitrary number of weights and weight values to be used in an electronic voting system. Design/methodology/approach – Robust Electronic Voting System (REVS) was chosen, a voting system designed to support internet voting processes, as the start point for studying the introduction of vote weights. Findings – The work resulted in an internet voting system supporting vote weights, based on REVS. Research limitations/implications – In the solution presented, there is still a problem regarding anonymity, for the case of a single voter with a particular weighted vote. This is a fundamental problem, since it also exists in paper-based elections. Practical implications – This version of REVS has the same properties as the original REVS, apart from the anonymity issue above. Apart from this the process of registering voters got more complicated, since now it includes an extra action for binding a weight. Originality/value – To the best of the authors' knowledge, this modified version of REVS is the first electronic voting system supporting vote weights. Another novelty of this work is the modulus sharing optimization used for the RSA key pairs of each entity.
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| 5. |
- Eliasson, Charlott, et al.
(författare)
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Dimensioning study for road user charging
- 2008
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Konferensbidrag (refereegranskat)abstract
- Road User Charging (RUC) solutions based on the concept of thin clients rely upon timely delivery of Heavy Goods Vehicles (HGV) positions towards a RUC provider, which then performs the map matching and the calculation of the road user charges. In order to avoid data loss and late delivery, a proper dimensioning of the system is required. For the Swedish case, we investigate the feasibility of legacy mobile and wireless systems (in particular GPRS, UMTS and WLAN) for both streaming and bulk transfer of positioning data, and we determine sensible combinations of sampling and reporting intervals in terms of efficient and economic reporting. We also highlight a couple of traps regarding the dimensioning, in particular of sending patterns that might cause overload at the server side of the system. It becomes obvious that mobile networks can well cope with the extra load caused by reporting HGVs, while bulk transfer in wireless hot-spots can be used as a complementary solution.
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| 6. |
- Eliasson, Charlott, et al.
(författare)
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Evaluation of Authentication Schemes Based on Security, User-Friendliness and Complexity
- 2008
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this work we are going to study and evaluate several SIMbased and non SIM-based authentication schemes for use in an IMS platform. The work will be done as part of the EUREKA!-funded Mobicome project. In this project eleven partners are participating in order to get a working prototype of the new generation network IMS to run. The major idea of the extended IMS functionality is seamlessness, both regarding network and device switching. Seamlessly working security solutions are a self-evident must in this context. In order to satisfy the customer while meeting technical boundary conditions, solutions must work in a satisfactory manner in many respects. On this background, this paper is a position paper, stating started and planned work on the evaluation of candidate security solutions for seamless IMS-based communications. First, the primary criteria of evaluation, namely security, user-friendliness and simplicity, are discussed. Then, the secondary criteria, which include awareness, usability and algorithms, are described. Along with the criteria, both sub-criteria and corresponding parameters are outlined. After this, the methodology for the evaluation is described. Finally, an outlook is presented at the end of the chapter.
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| 7. |
- Eliasson, Charlott
(författare)
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Quality of Experience and Quality of Service in the Context of an Internet-based Map Service
- 2008
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Increasingly many work processes depend on Information and Communication Technology (ICT) services. These define the efficiency of how tasks are solved. The perceived usability of a service is heavily linked to the performance of the service, for instance the service responsiveness. Users do not like to wait; long response times (RTs) will interrupt their flow of thoughts and finally result in a loss of interest. Quality aspects, seen from the user’s point of view, have gained importance. While the rather traditional notion Quality of Service (QoS) is mostly related to technical quality parameters of the actual data transport, the more recently established notion of Quality of Experience (QoE) extends the notion of quality to include user perception and expectations. Obviously, QoE has strong subjective components and is also connected to the situation and context in which the user finds him- or herself. This work aims at finding quantitative relationships between QoE and QoS in order to provide application designers with means to adapt their application to available networks and the related conditions. We have particularly focused on a Geographical Information System (GIS) Map Service, with a web-based client-server application, used amongst others by professional users for tasks of urban planning. We have conducted user experiments to derive the relationship between user-perceived QoE, expressed qualitatively (through comments) and quantitatively (on the well-known scale from 1 = worst to 5 = best), and the response time, i.e. the time the user has to wait for the execution of a command. We have then established quantitative relationships between the response time and network problems such as losses and delays that have been generated in a controlled way using a traffic shaper between client and server.
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| 8. |
- Eriksén, Sara, et al.
(författare)
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Mapping service quality : measuring and comparing quality of experience and quality of service for Internet-based map services
- 2007
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present an on-going research project in which we are focusing on examining how users of map-based services on-line experience the quality of these services when the traffic load is high, and how the users' experiences of acceptable or not acceptable quality can be related to measurable parameters which can be used to manage network traffic and improve technical solutions. The project is a multi- and interdisciplinary project in cooperation between researchers within human work science and informatics, and researchers within telecommunication systems. Additionally, there are two external partners in the project: a provider of Internet-based map services, and a municipality which uses this provider's map services regularly. One of the main methodological issues addressed in the project is how laboratory based, quantitative research methods from research on Quality of Service in the telecommunication systems area can be related to qualitative research methods focusing on workplace- or other live-world based use situations and Quality of Expereince as defined by users of the services. How can experiments and studies be designed, and results shared, such that both network traffic measuring and evaluation of user experiences retain their own paradigmatic validity and relevance, while fruitfully informing service design?
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| 9. |
- Fiedler, Markus, et al.
(författare)
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Parameterisation of a reputation system for VoIP in P2P networks for improved communication quality and security
- 2008
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we propose how to parameterize and maintain a reputation system that, based on the current network conditions, supports the selection of the optimal end-to-end communication path for VoIP communication in a P2P context. Each node’s reputation is formed based on three factors: (1) performance reputation (own experience from passive measures of the network conditions); (2) security reputation; and (3) information reputation consisting of recommendations from other nodes. Reputation data is periodically updated from continuous monitoring of path quality and security and also from information exchange between the nodes. When network conditions deteriorate, the reputation system enables switching, if possible, to another available path for furthercommunication. The proposed reputation system is a component of the SecMon system, which is intended especially for VoIP service over P2P networks. SecMon features lightweight QoS parameter monitoring, authentication and data integrity services. The exchange of monitoring information represents a low-bandwidth consumption solution that is transparent to the users and possesses a self-organizing capability. The above-mentioned exchange features are accomplished by utilizing two information hiding techniques: digital audio watermarking and network steganography. These techniques are used to create covert channels that serve as transport channels for lightweight QoS measurement results. Moreover, in this paper, we present results of the simulations that were performed to investigate how the proposed reputation system is performing for a simple twopath case scenario. Additionally, we show how different network conditions like delays and packet losses affect the proposed reputation system and how they are modeled with utility functions. Results of the simulations also illustrate the approaches to thresholds that trigger path changes.
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| 10. |
- Fiedler, Markus, et al.
(författare)
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Quality of Experience and Quality of Service in a Service Supply Chain
- 2007
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Extended Abstract: Quality of Service and Quality of Experience Networked ICT services keep on invading our private and professional lives. Increasingly many work processes depend on ICT services, which obviously define the efficiency of how tasks are solved. The perceived usability of a service is thereby heavily linked to the performance of the service, for instance its responsiveness. Users do not like to wait unnecessarily; long response times might interrupt their flow of thoughts and finally entail a loss of interest. Quality aspects seen from the user’s point of view have gained importance. Users rate the quality of the ICT services explicitly (by rating and commenting them) or implicitly (by using them happily, reluctantly or not at all). In case several alternative ICT services exist and pricing is not a primary matter of concern, quality may become the discriminating factor between different providers and might decide upon success or failure. While the rather traditional notion Quality of Service (QoS) is mostly related to technical quality parameters, the recently established notion of Quality of Experience (QoE) extends the notion of quality to include user perception. Obviously, QoE has strong subjective components and is also connected to the situation and context in which the user finds him- or herself. For instance, a certain response time of a service (e.g. providing an answer within four seconds) can be considered sufficient in a relaxed situation, but not when the user is in a stressed situation, e.g. having to make an urgent decision based on the result displayed by the service. User stress takes an impact on the threshold(s) marking off different levels of perception (excellent; good; fair; bad; etc.). More background to this particular issue is found in [2]. In the course of this work, we aim at finding quantitative relationships between the context in which the user finds him- or herself and the expectations regarding the – technical – performance in terms of QoS parameters such as the response time. Service Supply Chains Another important trend is the composition of tailored services, adapted to the needs of specific users in specific situations, out of basic service elements, potentially offered by different providers. Such a composite service forms a Service Supply Chain (SSC) consisting of one or several service elements. When the user activates the main service, the latter activates service elements as needed, handles the corresponding inputs, waits for deliveries, processes the corresponding outputs and finally returns the result to the user. The latter is sitting at the end of the SSC and has to wait for all service elements to finish before the result can be consumed. I.e., the user perceives the maximum of all response times in the system. In order to control user perception through service management, it is important to determine the weak links of SSC that provide the largest contributions to the response times in order to be able to cope with them in order to improve the user’s QoE perception. A particular case: Map-SSC In this work, we look at a particular service, a map service. These activities are part of a Swedish national project, funded by the Internet Infrastructure Foundation (.se) from funds earned by licensing Swedish Internet domains. We will observe professional users (planners at the municipality) in different stress situations when performing two map-related tasks, downloading a map and clicking a symbol in the displayed map in order to get more detailed information. The latter task relates to a SSC, consisting of a fetch-and-display service and an information service. Furthermore, we will introduce stress on network level by shaping the traffic. This will allow us to correlate user perception with thresholds of QoS parameters and thus to see the impact of user and/or network stress on Service Level Agreements (SLA). The map service provider participating in the project will instrument the SSC such that we will be able to monitor the response time at different places on application level in order to identify the critical links in the SSC. Furthermore, corresponding measurements on network level will be carried out in order to visualize the impact of the network stacks in client and servers, respectively.
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