Analysing Stream Authentication Protocols in Autonomous Agent-Based Systems

In stream authentication protocols used for large-scale data dissemination in autonomuous systems, authentication is based on the timing of the publication of keys, and depends on trust of the receiver in the sender and belief on whether an intruder can have prior knowledge of a key before it is published by a protocol. Many existing logics and approaches have successfully been applied to specify other types of authentication protocols, but most of them are not appropriate for analysing stream authentication protocols. We therefore consider a fibred modal logic that combines a belief logic with a linear-time temporal logic which can be used to analyse time-varying aspects of certain problems. With this logical system one is able to build theories of trust for analysing stream authentication protocols, which can deal with not only agent beliefs but also the timing properties of an autonomous agent-based system

Modal tableaux for verifying stream authentication protocols

To develop theories to specify and reason about various aspects of multi-agent systems, many researchers have proposed the use of modal logics such as belief logics, logics of knowledge, and logics of norms. As multi-agent systems operate in dynamic environments, there is also a need to model the evolution of multi-agent systems through time. In order to introduce a temporal dimension to a belief logic, we combine it with a linear-time temporal logic using a powerful technique called fibring for combining logics. We describe a labelled modal tableaux system for the resulting fibred belief logic (FL) which can be used to automatically verify correctness of inter-agent stream authentication protocols. With the resulting fibred belief logic and its associated modal tableaux, one is able to build theories of trust for the description of, and reasoning about, multi-agent systems operating in dynamic environments

Computational intelligent methods for trusting in social networks

104 p.This Thesis covers three research lines of Social Networks. The first proposed reseach line is related with Trust. Different ways of feature extraction are proposed for Trust Prediction comparing results with classic methods. The problem of bad balanced datasets is covered in this work. The second proposed reseach line is related with Recommendation Systems. Two experiments are proposed in this work. The first experiment is about recipe generation with a bread machine. The second experiment is about product generation based on rating given by users. The third research line is related with Influence Maximization. In this work a new heuristic method is proposed to give the minimal set of nodes that maximizes the influence of the network

Defeasible argumentation over relational databases

Defeasible argumentation has been applied successfully in several real-world domains in which it is necessary to handle incomplete and contradictory information. In recent years, there have been interesting attempts to carry out argumentation processes supported by massive repositories developing argumentative reasoning applications. One of such efforts builds arguments by retrieving information from relational databases using the DBI-DeLP framework; this article presents eDBI-DeLP, which extends the original DBI-DeLP framework by providing two novel aspects which refine the interaction between DeLP programs and relational databases. First, we expand the expressiveness of dbi-delp programs by providing ways of controlling how the information in databases is recovered; this is done by introducing filters that enable an improved fine-grained control on the argumentation processes which become useful in applications, providing the semantics and the implementation of such filters. Second, we introduce an argument comparison criterion which can be adjusted at the level of literals to model particular features such as credibility and topic expertise, among others. These new tools can be particularly useful in environments such as medical diagnosis expert systems, decision support systems, or recommender systems based on argumentation, where datasets are often provided in the form of relational databases.Fil: Deagustini, Cristhian Ariel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentina. Universidad Nacional de Entre Rios. Facultad de Ciencias Económicas; ArgentinaFil: Fulladoza Dalibón, Santiago Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentina. Universidad Nacional de Entre Rios. Facultad de Ciencias Económicas; ArgentinaFil: Gottifredi, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Falappa, Marcelo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentina. Universidad Nacional de Entre Rios. Facultad de Ciencias Económicas; ArgentinaFil: Chesñevar, Carlos Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Simari, Guillermo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentin

Automated security analysis of payment protocols

Thesis (Ph. D. in the Field of Computer Engineering)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 173-182).Formal analyses have been used for payment protocol design and verification but, despite developments in semantics and expressiveness, previous literature has placed little emphasis on the automation aspects of the proof systems. This research develops an automated analysis framework for payment protocols called PTGPA. PTGPA combines the techniques of formal analysis as well as the decidability afforded by theory generation, a general-purpose framework for automated reasoning. A comprehensive and self-contained proof system called TGPay is first developed. TGPay introduces novel developments and refinements in the formal language and inference rules that conform to the prerequisites of theory generation. These target desired properties in payment systems such as confidentiality, integrity, authentication, freshness, acknowledgement and non-repudiation. Common security primitives such as encryption, decryption, digital signatures, message digests, message authentication codes and X.509 certificates are modeled. Using TGPay, PTGPA performs analyses of payment protocols under two scenarios in full automation. An Alpha-Scenario is one in which a candidate protocol runs in a perfect environment without attacks from any intruders. The candidate protocol is correct if and only if all pre-conditions and post-conditions are met. PTGPA models actions and knowledge sets of intruders in a second, modified protocol that represents an attack scenario. This second protocol, called a Beta-Scenario, is obtained mechanically from the original candidate protocol, by applying a set of elementary capabilities from a Dolev-Yao intruder model. This thesis includes a number of case studies to demonstrate the feasibility and benefits of the proposed framework. Automated analyses of real-world bank card payment protocols as well as newly proposed contactless mobile payment protocols are presented. Security flaws are identified in some of the protocols; their causes and implications are addressed.by Enyang Huang.Ph.D.in the Field of Computer Engineerin

Public-Private Partnerships in Education & Education Reform: A New Theoretical & Applied Approach

Over the last four decades, there has been a significant increase in public-private education partnerships (PPPs). However, rather than reflecting the traditional PPP model where the private sector contributes resources to fulfill public policy agendas, businesses and philanthropies are partnering with urban schools to pursue their goals for reforming public education policy. With billions of dollars being spent by organizations like Microsoft, Meta, the Broad Foundation, and Bloomberg philanthropies on major initiatives to reform public education through teacher training and core curricular Changes, there has been surprisingly little research on the public-private partnership model itself and its impact on education policy. This dissertation intends to address this research gap by considering how public-private partnerships have been traditionally defined and explained in public policy and political science; what has Changed in the structure and purpose of public-private partnerships in education; how do we define and understand an educational public-private partnership in the current context; how do we determine what makes public-private partnerships successful; and based on this new definition, how do we understand their impact on educational public policy priorities? The dissertation aims to accomplish the following: 1) Discuss the existing public policy and political science literature on public-private partnerships. 2) Use anecdotal evidence, research literature, and news reporting to propose a framework for what public-private partnerships in education entail now and what their outcomes appear to be. 3) Identify key performance indicators (KPIs) of success from that literature and test their relevance to the success of current educational PPPs – towards formalizing a new theoretical definition and future guide for applied research. 4) Use both quantitative and qualitative research methods on a sample of partnerships which have already been documented either through original research or third party analytical and narrative reports to analyze and define those key performance indicators which are relevant to current educational PPPs. 5) Through analysis of the intended and actual outcomes of those PPP cases used in previous analysis, demonstrate how current educational PPPs are now both formulating and implementing policy. The importance of this finding is related to debates about the purpose of public education, the definition of public goods, and democratic accountability. 6) Identify the gap between the existing theoretical definition of PPPs and the derived newly proposed framework and the implications for theory, practice and policy. 7) Through a synthesis of the above items, construct an original method and tool for how to form and assess these partnerships for successful outcomes, as well as effective policy.  Applied Qualitative Research The third paper utilizes data from the quantitative research of paper 2 and builds and expands on the findings by using a qualitative methodology to analyze cases which have a more robust narrative. The cases I consider are Bloomberg philanthropies Global Scholars and Mark Zuckerberg’s Newark public schools. I document the functional, political, and financial differences between the cases, as well as how the PPPs were implemented. This applied research considers the indicators which proved relevant in the prior quantitative research through a qualitative analysis of materials, reports, and interviews. Applied Quantitative Research This second paper is applied quantitative research and serves as the bridge between the literature and theory to current applications and directs the focus of the subsequent applied qualitative research in this dissertation. I take the elements identified as standard KPIs from literature and prior research studies and using the documentation from the united way portfolio I test the relevance of those existing KPIs to the current theoretical framework. The Detroit cases are ideal for this portion of the research as those cases were created as PPPs and concluded (at least as far as an initial MOU agreement) within a specific timeframe. I collected all the documentation on those partnerships and their elements using a measurement system I developed. I use a quantitative method of binary logic regression to consider, given the documented outcomes of those cases, whether there is simple significance of an indicator as it relates to a quantitative definition of success. My metric is whether more than 50% of the objectives outlined in the MOUs were successfully completed. The quantitative methodology is important, because it allows us to determine which indicators remain relevant and warrant further study. At the end of this paper the advantages and limitations of quantitative analysis will be discussed, as well as thoughts about how qualitative analysis may help further the research going forward. This serves as a bridge to the next section/chapter. The purpose of this paper is to move beyond simply identifying components of the PPPs, as was done in the second paper, to more fully articulate and define them. I also identify the variance in PPP outcomes which may come from leadership structure, organizational occupation (for profit, nonprofit, public) and other operational and political variables. This section draws heavily on my research which uses a qualitative comparative frame to analyze the BP and Zuckerberg cases. The importance of these findings, as well as the advantages and limitations of this methodology are also be discussed. Toward a Theoretical Framework for PPPs & a New Tool for Evaluation Research The third paper of the dissertation synthesizes the analysis from the previous two papers in order to integrate both sets of findings and limitations in order to better define and understand current educational PPPs. This will lead to a new proposed theory of PPPs in education, to be followed by an analytic discussion, which will rely on research I have already done. The new proposed theory will be compared to the existing theory. The empirical evidence will make clear that new forms of PPPs have been implemented that are not accounted for in the existing theory. The implications of these findings will be important for both public and private actors who will need to think about and formulate PPPs in different ways than they have been doing. Once this is explicated, I consider the implications of substituting PPPs for the traditional policymaking process, and what can reasonably be anticipated as outcomes for public goods and democratic accountability. PPPs must be understood as an alternative pathway to policymaking which most often will not include traditional policy makers, and by virtue of financial and operational conditions, will fast track educational reforms. This increase in speed and coherence of reform is likely to be accompanied by a decline in democratic accountability, which particularly as it concerns public K-12 education, may fundamentally change the nature of that specific public good, and may even extend to a larger reconceptualization in the country of the concept of public goods. The last section of the third paper moves from the theoretical to the applied. This section discusses how the research gathered and synthesized in the previous two papers contributes to an applied framework for formulating and assessing educational PPPs for rates of success. This is especially important as we can expect that there will not be a decline in educational PPPs, but rather an ever-growing prevalence of them in American public education systems. I then make the case specifically for the use of comparative-qualitative analysis as an appropriate analytic frame for an evaluation tool. The section then goes on to detail the development of this tool, which relies on the methods and findings of the previous applied research sections in the dissertation. I provide a methodology for documenting the qualitative elements to be observed through an interview protocol, as well as the methodology by which that qualitative data can be converted to a quantitative value using previously discussed key variables and then cross-assessed with other related variables, weighted, and inputted into a prescribed algorithm (using analytics frames from educational performance evaluations, quantitative regression, and machine learning prediction principles). This will produce a predictive outcome of success and a meta frame to compare and contrast different educational PPPs going forward. This aspect of the research is important, as it provides practitioners, educators, policymakers, and public and private leadership a better understanding of what in fact they are doing when attempting to formulate and implement a public private partnership; what elements they should seek to build into their partnership in order to create increased conditions for successful outcomes; and finally how as researchers, we might, in the future, have a tool to observe, track, and evaluate these partnerships to further our theoretical and applied understanding of educational policy

Trust management and trust theory revision

A theory of trust for a given system consists of a set of rules that describe trust of agents in the system. In a certain logical framework, the theory is generally established based on the initial trust of agents in the security mechanisms of the system. Such a theory provides a foundation for reasoning about agent beliefs as well as security properties that the system may satisfy. However, trust changes dynamically. When agents lose their trust or gain new trust in a dynamic environment, the theory established based on the initial trust of agents in the system must be revised, otherwise it can no longer be used for any security purpose. This paper investigates the factors influencing trust of agents and discusses how to revise theories of trust in dynamic environments. A methodology for revising and managing theories of trust for multiagent systems is proposed. This methodology includes a method for modeling trust changes, a method for expressing theory changes, and a technique for obtaining a new theory based on a given trust change. The proposed approach is very general and can be applied to obtain an evolving theory of trust for agent-based systems.10 page(s