Asymptotically idempotent aggregation operators for trust management in multi-agent systems

The study of trust management in multi-agent system, especially distributed, has grown over the last years. Trust is a complex subject that has no general consensus in literature, but has emerged the importance of reasoning about it computationally. Reputation systems takes into consideration the history of an entity’s actions/behavior in order to compute trust, collecting and aggregating ratings from members in a community. In this scenario the aggregation problem becomes fundamental, in particular depending on the environment. In this paper we describe a technique based on a class of asymptotically idempotent aggregation operators, suitable particulary for distributed anonymous environments

A Distributed Context-Aware Trust Management Architecture

The realization of a pervasive context-aware service platform imposes new challenges for the security and privacy aspects of the system in relation to traditional service platforms. One important aspect is related with the management of trust relationships, which is especially hard in a pervasive environment because users are supposed to interact with entities unknown before hand in an ad-hoc and dynamic manner. Current trust management solutions do not adapt nor scale well in this dynamic service provisioning scenario because they require previously defined trust relationships in order to operate. The objective of this thesis is to design, prototype and validate a context-aware distributed trust management architecture in order to address: (a) the lack of integration between available trust solutions and security and privacy management languages, and (b) the dynamic characteristics of a context-aware service platform

SPADE: SPKI/SDSI for Attribute Release Policies in a Distributed Environment

Shibboleth is a federated administrated system that supports inter-institutional authentication and authorization for sharing of resources. SPKI/SDSI is a public key infrastructure whose creation was motivated by the perception that X.509 is too complex and flawed. This thesis addresses the problem of how users that are part of a Public Key Infrastructure in a distributed computing system can effectively specify, create, and disseminate their Attribute Release Policies for Shibboleth using SPKI/SDSI. This thesis explores existing privacy mechanims, as well as distributed trust management and policy based systems. My work describes the prototype for a Trust Management Framework called SPADE (SPKI/SDSI for Attribute Release Policies in a Distributed Environment) that I have designed, developed and implemented. The principal result of this research has been the demonstration that SPKI/SDSI is a viable approach for trust management and privacy policy specification, especially for minimalistic policies in a distributed environment

Authentication and authorisation in entrusted unions

This paper reports on the status of a project whose aim is to implement and demonstrate in a real-life environment an integrated eAuthentication and eAuthorisation framework to enable trusted collaborations and delivery of services across different organisational/governmental jurisdictions. This aim will be achieved by designing a framework with assurance of claims, trust indicators, policy enforcement mechanisms and processing under encryption to address the security and confidentiality requirements of large distributed infrastructures. The framework supports collaborative secure distributed storage, secure data processing and management in both the cloud and offline scenarios and is intended to be deployed and tested in two pilot studies in two different domains, viz, Bio-security incident management and Ambient Assisted Living (eHealth). Interim results in terms of security requirements, privacy preserving authentication, and authorisation are reported

Integrated Social and Quality of Service Trust Management of Mobile Groups in Ad Hoc Networks

Abstract—We propose to combine social trust derived from social networks with quality-of-service (QoS) trust derived from communication networks to obtain a composite trust metric as a basis for evaluating trust of mobile nodes in mobile ad hoc network (MANET) environments. We develop a novel modelbased approach to identify the best protocol setting under which trust bias is minimized, that is, the peer-to-peer subjective trust as a result of executing our distributed trust management protocol is close to ground truth status over a wide range of operational and environment conditions with high resiliency to malicious attacks and misbehaving nodes. Keywords—trust management; mobile ad hoc networks; QoS trust; social trust; trust bias minimization. I

Enhancing Trust Management in Cloud Environment

AbstractTrust management has been identified as vital component for establishing and maintaining successful relational exchanges between e-commerce trading partners in cloud environment. In this highly competitive and distributed service environment, the assurances are insufficient for the consumers to identify the dependable and trustworthy Cloud providers. Due to these limitations, potential consumers are not sure whether they can trust the Cloud providers in offering dependable services. In this paper, we propose a multi-faceted trust management system architecture for cloud computing marketplaces, to support customers in identifying trustworthy cloud providers. This paper presents the important threats to a trust system and proposed a method for tackling these threats. It described the desired feature of a trust management system. It security components to determine the trustworthiness of e- commerce participants to helps online customers to decide whether or not to proceed with a transaction. Based on this framework, we proposed an approach for filtering out malicious feedbacks and a trust metric to evaluate the trustworthiness of service provider. Results of various simulation experiments show that the proposed multi-attribute trust management system can be highly effective in identifying risky transaction in electronic market places

An Operational Semantics for Trust Policies.

In the trust-structure model of trust management, principals specify their trusting relationships with other principals in terms of trust policies. In their paper on trust structures, Carbone et al. present a language for trust policies, and provide a suitable denotational semantics. The semantics ensures that for any collection of trust policies, there is always a unique global trust-state, compatible with all the policies, specifying everyone's degree of trust in everyone else. However, as the authors themselves point out, the language lacks an operational model: the global trust-state is a well-defined mathematical object, but it is not clear how principals can actually compute it. This becomes even more apparent when one considers the intended application environment: vast numbers of autonomous principals, distributed and possibly mobile. We provide a compositional operational semantics for a language of trust policies. The operational semantics is given in terms of a composition of I/O automata. We prove that this semantics is faithful to its corresponding denotational semantics, in the sense that any run of the I/O automaton ``converges to'' the denotational semantics of the policies. Furthermore, as I/O automata are a natural model of asynchronous distributed computation, the semantics leads to an algorithm for distributedly computing the trust-state, which is suitable in the application environment

Trust-as-a-Service: A reputation-enabled trust framework for 5G network resource provisioning

Trust, security, and privacy are three of the major pillars to assemble the fifth-generation network and beyond. Despite such pillars are principally interconnected, a multitude of challenges arise that need to be addressed separately. 5G networks ought to offer flexible and pervasive computing capabilities across multiple domains according to user demands and assure trustworthy network providers. To this end, distributed marketplaces expect to boost the trading of heterogeneous resources so as to enable the establishment of pervasive service chains between cross-domains. Yet, the need for selecting reliable parties as “marketplace operators” plays a pivotal role in achieving a trustworthy ecosystem. Two of the principal blockages in managing foreseeable networks are the need to consider trust as a property in the resource provisioning process and adapt previous trust models to accomplish the new network and business requirements. In this regard, this article is centered on the trust management of 5G multi-party network resource provisioning. As a result, a reputation-based trust framework is proposed as a Trust-as-a-Service (TaaS) solution for a distributed multi-stakeholder environment where requirements such as zero trust and zero-touch principles should be met. Besides, a literature review is also conducted to recognize the network and business requirements currently envisaged. Finally, the validation of the proposed trust framework was performed in a real research environment, the 5GBarcelona testbed, leveraging 12% of a 2.1 GHz CPU with 20 cores and 2% of the 30 GiB memory. These outcomes reveal the TaaS solution’s feasibility and conservative approach in the context of determining reliable network operators