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Proceedings of the 10th IFIP WG 11.11 International Conference on Trust Management (IFIPTM 2016)
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Trust Establishment Mechanisms for Distributed Service Environments
No full textThe aim and motivation of this dissertation can be best described in one of the most important application fields, the cloud computing. It has changed entire business model of service-oriented computing environments in the last decade. Cloud computing enables information technology related services in a more dynamic and scalable way than before – more cost-effective than before due to the economy of scale and of sharing resources. These opportunities are too attractive for consumers to ignore in today’s highly competitive service environments. The way to realise these opportunities, however, is not free of obstacles. Services offered in cloud computing environments
are often composed of multiple service components, which are
hosted in distributed systems across the globe and managed by multiple
parties. Potential consumers often feel that they lose the control over their data, due to the lack of transparent service specification and unclear security assurances in such environments. These issues encountered by the consumers boiled down to an unwillingness to depend on the service providers regarding the services they offer in the marketplaces. Therefore, consumers have to be put in a position where they can reliably assess the dependability of a service provider. At the same time, service providers have to be able to truthfully present the service-specific security capabilities. If both of these objectives can be achieved, consumers have a basis to make well-founded decisions about whether or not to depend on a particular service provider out of many alternatives.
In this thesis, computational trust mechanisms are leveraged to assess the capabilities and evaluate the dependability of service providers. These mechanisms, in the end, potentially support consumers to establish trust on service providers in distributed service environments, e.g., cloud computing. In such environments, acceptable quality of the services can be maintained if the providers possess required capabilities regarding different service-specific
attributes, e.g., security, performance, compliance. As services in
these environments are often composed of multiple services, subsystems and components, evaluating trustworthiness of the service providers based on the service-specific attributes is non-trivial.
In this vein, novel mechanisms are proposed for assessing and evaluating the trustworthiness of service providers considering the trustworthiness of composite services. The scientific contributions towards those novel mechanisms are summarised as follows:
• Firstly, we introduce a list of service-specific attributes, QoS+ [HRM10, HHRM12], based on a systematic and comprehensive analysis of existing literatures in the field of cloud computing security and trust.
• Secondly, a formal framework [SVRH11, RHMV11a, RHMV11b] is
proposed to analyse the composite services along with their required
service-specific attributes considering consumer requirements and represent them in simplified meaningful terms, i.e., Propositional Logic Terms (PLTs).
• Thirdly, a novel trust evaluation framework CertainLogic [RHMV11a,
RHMV11b, HRHM12a, HRHM12b] is proposed to evaluate the PLTs,
i.e., capabilities of service providers. The framework provides computational operators to evaluate the PLTs, considering that uncertain and conflicting information are associated with each of the PLTs and those information can be derived from multiple sources.
• Finally, harnessing these technical building blocks we present a novel trust management architecture [HRM11] for cloud computing marketplaces. The architecture is designed to support consumers in assessing and evaluating the trustworthiness of service providers based on the published information about their services.
The novel contributions of this thesis are evaluated using proof-of-concept-system, prototype implementations and formal proofs. The proof-of-concept-system [HRMV13, HVM13a, HVM13b] is a realisation of the proposed architecture for trust management in cloud marketplaces. The realisation of the system is implemented based on a self-assessment framework, proposed by the Cloud Security Alliance, where the formal framework and computational operators of CertainLogic are applied. The realisation of the system enables consumers to evaluate the trustworthiness of service providers based on their published datasets in the CSA STAR. A number of experiments are conducted in different cloud computing scenarios leveraging the datasets in order to demonstrate the technical feasibility of the contributions made in this thesis. Additionally, the prototype implementations of CertainLogic framework provide means to demonstrate the characteristics of the computational operators by means of various examples. The formal framework as well as computational operators of CertainLogic are validated against desirable mathematical properties, which are supported by formal algebraic proofs
Security Evaluation of the Windows Mobile Operating System
No full textSmartphones are rapidly replacing the traditional cellular phones because of its PC-like features which allow them to be used as web browsers, editors and media players. These devices run complete operating systems that allow installation of third party applications. As their usage grows, the need for securing the user data stored on these devices and the services that they provide becomes more and more vital. Mobile Operating Systems naturally become the target for security scrutiny as they are responsible for managing all the information and services.
Our report analyzes the Windows Mobile 6.1 operating system and its security features. We have looked into the OS architecture, memory management, process management, file system, device drivers and communication service and network stack architecture. We have analyzed its security model and looked into some of the related research work regarding the operating system’s security. Moreover, penetration testing against the Windows Mobile 6.1 operating system has been performed to show the stability and robustness of the network stack in a hostile environment. At last, security issues are discussed in detail from an application’s perspective in order to show what type of (security) problems are faced by an application and what improvements are needed to counter those threats. In a whole, this report identifies the strengths and weaknesses of the Windows Mobile operating system. The aim of this report is to create awareness in this area and to encourage further research into mobile operating system security
Security Evaluation of the Windows Mobile Operating System
No full textSmartphones are rapidly replacing the traditional cellular phones because of its PC-like features which allow them to be used as web browsers, editors and media players. These devices run complete operating systems that allow installation of third party applications. As their usage grows, the need for securing the user data stored on these devices and the services that they provide becomes more and more vital. Mobile Operating Systems naturally become the target for security scrutiny as they are responsible for managing all the information and services. Our report analyzes the Windows Mobile 6.1 operating system and its security features. We have looked into the OS architecture, memory management, process management, file system, device drivers and communication service and network stack architecture. We have analyzed its security model and looked into some of the related research work regarding the operating system’s security. Moreover, penetration testing against the Windows Mobile 6.1 operating system has been performed to show the stability and robustness of the network stack in a hostile environment. At last, security issues are discussed in detail from an application’s perspective in order to show what type of (security) problems are faced by an application and what improvements are needed to counter those threats. In a whole, this report identifies the strengths and weaknesses of the Windows Mobile operating system. The aim of this report is to create awareness in this area and to encourage further research into mobile operating system security
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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