77 research outputs found

    Methodologies synthesis

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    This deliverable deals with the modelling and analysis of interdependencies between critical infrastructures, focussing attention on two interdependent infrastructures studied in the context of CRUTIAL: the electric power infrastructure and the information infrastructures supporting management, control and maintenance functionality. The main objectives are: 1) investigate the main challenges to be addressed for the analysis and modelling of interdependencies, 2) review the modelling methodologies and tools that can be used to address these challenges and support the evaluation of the impact of interdependencies on the dependability and resilience of the service delivered to the users, and 3) present the preliminary directions investigated so far by the CRUTIAL consortium for describing and modelling interdependencies

    On Trust Establishment in Mobile Ad-Hoc Networks

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    We present some properties of trust establishment in mobile, ad-hocnetworks and illustrate how they differ from those of trustestablishment in the Internet. We motivate these differences byproviding an example of ad-hoc network use in battlefield scenarios,yet equally practical examples can be found in non-militaryenvironments. We present a framework for trust establishment inmobile ad-hoc networks and argue that peer-to-peer networks areespecially suitable to solve the problems of generation, distribution,and discovery of trust evidence in mobile ad-hoc networks. We evaluateour approach through simulation with NS-2

    Security and Privacy of IP-ICN Coexistence: A Comprehensive Survey

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    Internet usage has changed from its first design. Hence, the current Internet must cope with some limitations, including performance degradation, availability of IP addresses, and multiple security and privacy issues. Nevertheless, to unsettle the current Internet's network layer i.e., Internet Protocol with ICN is a challenging, expensive task. It also requires worldwide coordination among Internet Service Providers , backbone, and Autonomous Services. Additionally, history showed that technology changes e.g., from 3G to 4G, from IPv4 to IPv6 are not immediate, and usually, the replacement includes a long coexistence period between the old and new technology. Similarly, we believe that the process of replacement of the current Internet will surely transition through the coexistence of IP and ICN. Although the tremendous amount of security and privacy issues of the current Internet taught us the importance of securely designing the architectures, only a few of the proposed architectures place the security-by-design. Therefore, this article aims to provide the first comprehensive Security and Privacy analysis of the state-of-the-art coexistence architectures. Additionally, it yields a horizontal comparison of security and privacy among three deployment approaches of IP and ICN protocol i.e., overlay, underlay, and hybrid and a vertical comparison among ten considered security and privacy features. As a result of our analysis, emerges that most of the architectures utterly fail to provide several SP features including data and traffic flow confidentiality, availability and communication anonymity. We believe this article draws a picture of the secure combination of current and future protocol stacks during the coexistence phase that the Internet will definitely walk across

    Department of Computer Science Activity 1998-2004

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    This report summarizes much of the research and teaching activity of the Department of Computer Science at Dartmouth College between late 1998 and late 2004. The material for this report was collected as part of the final report for NSF Institutional Infrastructure award EIA-9802068, which funded equipment and technical staff during that six-year period. This equipment and staff supported essentially all of the department\u27s research activity during that period

    A STUDY OF GRAPHICAL ALTERNATIVES FOR USER AUTHENTICATION

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    Merged with duplicate record 10026.1/1124 on 27.02.2017 by CS (TIS)Merged with duplicate record 10026.1/1124 Submitted by Collection Services ([email protected]) on 2012-08-07T10:49:43Z No. of bitstreams: 1 JALI MZ_2011.pdf: 7019966 bytes, checksum: e2aca7edf5e11df083ec430aedac512f (MD5) Approved for entry into archive by Collection Services([email protected]) on 2012-08-07T10:50:20Z (GMT) No. of bitstreams: 1 JALI MZ_2011.pdf: 7019966 bytes, checksum: e2aca7edf5e11df083ec430aedac512f (MD5) Made available in DSpace on 2012-08-07T10:50:20Z (GMT). No. of bitstreams: 1 JALI MZ_2011.pdf: 7019966 bytes, checksum: e2aca7edf5e11df083ec430aedac512f (MD5) Previous issue date: 2011Authenticating users by means of passwords is still the dominant form of authentication despite its recognised weaknesses. To solve this, authenticating users with images or pictures (i.e. graphical passwords) is proposed as one possible alternative as it is claimed that pictures are easy to remember, easy to use and has considerable security. Reviewing literature from the last twenty years found that few graphical password schemes have successfully been applied as the primary user authentication mechanism, with many studies reporting that their proposed scheme was better than their predecessors and they normally compared their scheme with the traditional password-based. In addition, opportunities for further research in areas such as image selection, image storage and retrieval, memorability (i.e. the userā€™s ability to remember passwords), predictability, applicability to multiple platforms, as well as usersā€™ familiarity are still widely possible. Motivated by the above findings and hoping to reduce the aforementioned issues, this thesis reports upon a series of graphical password studies by comparing existing methods, developing a novel alternative scheme, and introducing guidance for users before they start selecting their password. Specifically, two studies comparing graphical password methods were conducted with the specific aims to evaluate usersā€™ familiarity and perception towards graphical methods and to examine the performance of graphical methods in the web environment. To investigate the feasibility of combining two graphical methods, a novel graphical method known as EGAS (Enhanced Graphical Authentication System) was developed and tested in terms of its ease of use, ideal secret combination, ideal login strategies, effect of using smaller tolerances (i.e. areas where the click is still accepted) as well as usersā€™ familiarity. In addition, graphical password guidelines (GPG) were introduced and deployed within the EGAS prototype, in order to evaluate their potential to assist users in creating appropriate password choices. From these studies, the thesis provides an alternative classification for graphical password methods by looking at the usersā€™ tasks when authenticating into the system; namely click-based, choice-based, draw-based and hybrid. Findings from comparative studies revealed that although a number of participants stated that they were aware of the existence of graphical passwords, they actually had little understanding of the methods involved. Moreover, the methods of selecting a series of images (i.e. choice-based) and clicking on the image (i.e. click-based) are actually possible to be used for web-based authentication due to both of them reporting complementary results. With respect to EGAS, the studies have shown that combining two graphical methods is possible and does not introduce negative effects upon the resulting usability. User familiarity with the EGAS software prototype was also improved as they used the software for periods of time, with improvement shown in login time, accuracy and login failures. With the above findings, the research proposes that usersā€™ familiarity is one of the key elements in deploying any graphical method, and appropriate HCI guidelines should be considered and employed during development of the scheme. Additionally, employing the guidelines within the graphical method and not treating them as a separate entity in user authentication is also recommended. Other than that, elements such as reducing predictability, testing with multiple usage scenarios and platforms, as well as flexibility with respect to tolerance should be the focus for future research

    A comprehensive view on quantity based aggregation for cadastral databases

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    Quantity Based Aggregation (QBA) control is a subject that is closely related to inference control in databases. The goal is to enforce k out of n disclosure control. In this paper we work on QBA problems in the context of cadastral databases: how to prevent a user from knowing 1) the owners of all parcels in a region, and 2) all parcels belonging to the same owner. This work combines and extends our previous work on the subject [1, 2, 3]. We overview the legislative context surrounding cadastral databases. We give important definitions related to the QBA concept. We present a complete model for QBA control in cadastral databases. We show how to implement the security policy efficiently, and we present our prototype of secure cadastral databases with some performance evaluations

    Secure Mobile Agent from Leakage-Resilient Proxy Signatures

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    A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator) to delegate its signing right to another entity (proxy) to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems

    Integration of analysis techniques in security and fault-tolerance

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    This thesis focuses on the study of integration of formal methodologies in security protocol analysis and fault-tolerance analysis. The research is developed in two different directions: interdisciplinary and intra-disciplinary. In the former, we look for a beneficial interaction between strategies of analysis in security protocols and fault-tolerance; in the latter, we search for connections among different approaches of analysis within the security area. In the following we summarize the main results of the research
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