Transitive Trust Research Articles

Measurement Theory-Based Trust Management Framework for Online Social Communities

We propose a trust management framework based on measurement theory to infer indirect trust in online social communities using trust’s transitivity property. Inspired by the similarities between human trust and measurement, we propose a new trust metric, composed of impression and confidence, which captures both trust level and its certainty. Furthermore, based on error propagation theory, we propose a method to compute indirect confidence according to different trust transitivity and aggregation operators. We perform experiments on two real data sets, Epinions.com and Twitter, to validate our framework. Also, we show that inferring indirect trust can connect more pairs of users.

An enhanced and secure trust‐extended authentication mechanism for vehicular ad‐hoc networks

AbstractVehicular Ad‐hoc Networks (VANETs) are a move towards regulating safe traffic and intelligent transportation system. A VANETs is characterized by extremely dynamic topographical conditions owing to speedily moving vehicles. In VANETs, vehicles can transmit messages within a pre‐defined area to achieve safety and efficiency of the system. Then ensuring authenticity of origin of messages to the receiver in such a dynamic environment is a crucial challenge. Another concern in VANET is preservation of privacy of user/vehicle. Recently, Chuang and Lee proposed a trust‐extended authentication mechanism (TEAM) for vehicle‐to‐vehicle communications in VANETs. TEAM not only satisfies various security features but also enhances the performance of the authentication process using transitive trust relationship among vehicles. Nonetheless, our analysis shows that TEAM is vulnerable to insider attack, privacy breach, impersonation attacks and some other problems. In this paper, to eradicate the vulnerabilities found in Chuang‐Lee's scheme, an enhanced trust‐extended authentication scheme for VANET is proposed. We display the efficiency of our scheme through security analysis and comparison. Through simulation results using widely accepted NS‐2 simulator, we show that our scheme authenticates vehicles faster than Chuang‐Lee's scheme. Copyright © 2016 John Wiley & Sons, Ltd.

TISoN

Trust systems represent a significant trend in decision support for social networks’ service provision. The basic idea is to allow users to rate each other even without being direct neighbours. In this case, the purpose is to derive a trust score for a given user, which could be of help to decide whether to trust other users or not. In this article, we investigate the properties of trust propagation within social networks, based on the notion of transitivity , and we introduce the TISoN model to generate and evaluate T rust I nference within online So cial N etworks. To do so, ( i ) we develop a novel TPS algorithm for T rust P ath S earching where we define neighbours’ priority based on their direct trust degrees, and then select trusted paths while controlling the path length; and, ( ii ) we develop different TIM algorithms for T rust I nference M easuring and build a trust network. In addition, we analyse existing algorithms and we demonstrate that our proposed model better computes transitive trust values than do the existing models. We conduct extensive experiments on a real online social network dataset, Advogato. Experimental results show that our work is scalable and generates better results than do the pioneering approaches of the literature.

A trust model for recommender agent systems

This paper aims to improve trust models in multi-agent systems based on four vital components, namely: reliability, similarity, satisfaction and trust transitivity. A number of different methods of computing these components were analyzed by considering the most representative existing trust models. The four trust components were identified from existing models then a trust model named trust transitivity---satisfaction---similarity---reliability (TtSSR) was proposed based on these components. TtSSR applied fuzzy logic for computing the identified components. Then by integrating the identified components and using Technique for Order of Preference by Similarity to Ideal Solution as a decision-making method, TtSSR selects the most trustworthy provider agent. The performance of TtSSR was compared with existing trust models using a simulator, specifically with Bayesian Network Model, Probability Certainty Distribution Model, and Dynamic Trust Model which are based on probability and TREPPS which is based on fuzzy logic. The experimental results revealed that TtSSR can significantly improve the accuracy of trust models; while the result of simulations demonstrated that the average accuracy of TtSSR in selecting a trustworthy agent is better than other models. Generally, the results indicated that when these four components were integrated, they performed significantly better in selecting a trustworthy agent as compared to other models.

Trust Description and Propagation System: Semantics and axiomatization

Trust plays a vital role in many successful applications in computer science. However, existing work fails to provide a systematic analysis of trust in a consistent logic framework, resulting in the fact that trust can only be used pragmatically and even be misused. Therefore, in the form of language, semantics and axiomatization, we propose a sound and complete trust logical system named Trust Description and Propagation System (TDPS). TDPS gives a formal language that can explicitly define the various trusts: direct belief trust, direct commitment trust, meta belief trust and meta commitment trust. In terms of possible states, our TDPS semantic model can formally interpret the different meanings of trust and their degrees (trust, distrust and untrust) in logic. Based on the semantic model, we derive the trust calculation mechanism instead of using heuristics. Moreover, we propose and demonstrate a sound and complete trust deduction system to rigorously discern and define the transitivity of trust, which provides a firm theoretic and logical foundation for various trust applications. Through demo examples generalized from real e-business applications, we show how to use the TDPS system to represent, calculate and refer the various trust relationships.

A referral-functional trust perspective for enhanced recommendations

There has been considerable interest recently in trust-enhanced recommender systems (RS). Trust is employed as an aid to overcome the sparsity problem in recommender systems (RS) by utilising the web of trust to discover proximity between users who can otherwise not be deemed similar. Such similar user discovery process utilises trust transitivity to infer the quantum of trust between a pair of users who do not have a trust link between them but are connected through the network. This enables broadening the set of users contributing to the recommendation. However, most trust-based approaches for RS do not distinguish between the trust in a party to suggest items (functional trust) and the trust in a party to recommend good recommenders (referral trust). We propose a referral-functional trust approach to RS suggesting different ways of modelling referral trust for a binary trust network and incorporating it in the trust propagation scheme to obtain better quality recommendations. Our approaches utilise the quality of the neighbourhood offered through a user’s connections to estimate the user’s referring capacity. The experimental results, showing comparison with existing schemes for trust inference, have established the effectiveness of our approach.

TEAM: Trust-Extended Authentication Mechanism for Vehicular Ad Hoc Networks

The security of vehicular ad hoc networks (VANETs) has been receiving a significant amount of attention in the field of wireless mobile networking because VANETs are vulnerable to malicious attacks. A number of secure authentication schemes based on asymmetric cryptography have been proposed to prevent such attacks. However, these schemes are not suitable for highly dynamic environments such as VANETs, because they cannot efficiently cope with the authentication procedure. Hence, this still calls for an efficient authentication scheme for VANETs. In this paper, we propose a decentralized lightweight authentication scheme called trust-extended authentication mechanism (TEAM) for vehicle-to-vehicle communication networks. TEAM adopts the concept of transitive trust relationships to improve the performance of the authentication procedure and only needs a few storage spaces. Moreover, TEAM satisfies the following security requirements: anonymity, location privacy, mutual authentication, forgery attack resistance, modification attack resistance, replay attack resistance, no clock synchronization problem, no verification table, fast error detection, perfect forward secrecy, man-in-the-middle attack resistance, and session key agreement.

Self-organized public key management in MANETs with enhanced security and without certificate-chains

In the self-organized public key management approaches, public key verification is achieved through verification routes constituted by the transitive trust relationships among the network principals. Most of the existing approaches do not distinguish among different available verification routes. Moreover, to ensure stronger security, it is important to choose an appropriate metric to evaluate the strength of a route. Besides, all of the existing self-organized approaches use certificate-chains for achieving authentication, which are highly resource consuming. In this paper, we present a self-organized certificate-less on-demand public key management (CLPKM) protocol, which aims at providing the strongest verification routes for authentication purposes. It restricts the compromise probability for a verification route by restricting its length. Besides, we evaluate the strength of a verification route using its end-to-end trust value. The other important aspect of the protocol is that it uses a MAC function instead of RSA certificates to perform public key verifications. By doing this, the protocol saves considerable computation power, bandwidth and storage space. We have used an extended strand space model to analyze the correctness of the protocol. The analytical, simulation, and the testbed implementation results confirm the effectiveness of the proposed protocol.

Transitivity of Agent Subjective Trust

Researches on trust have attracted more and more attentions in multi-agent systems and networks.However,subjective trust generally has no transitivity,which brings much non-determination on delegation,network information propagation,and the construction of subjective trust network.To this end,the paper discusses the binary value of trust relation,and its transitivity in cooperative environment.First,the study gives the definition of objective trust and subjective trust.Next,the paper proposes some useful properties of trust related to the transitivity of trust and demonstrates that objective trust has a relation of equivalence,and subjective trust has a relation of constrained symmetry and transitivity.Finally,a feasible algorithm of subjective trust closure and test algorithms for connectedness are given,and the study has demonstrated that the computational complexities of the above algorithms are polynomial order.The paper made some initial explores on transitivity of subjective trust and gives some useful basic conclusions.

Living in an Impossible World: Real-izing the Consequences of Intransitive Trust

Many accounts of online trust are based upon mechanisms for building reputation. Trust is portrayed as desirable, and handing off trust is easier if trust is modelled to be transitive. But in the analysis of cyber-security protocols, trust is usually used as a substitute for certain knowledge: it follows that if there is no residual risk, then there is no need for trust. On this grimmer understanding, the less that users are required to trust, the better. Involuntary transitivity of trust becomes corrosive, because it prevents participants from having control—or even knowledge—of the risks to which their trust assumptions expose them. In this paper, we take the stance that controlling the transitivity of trust requires us to recognise trust as a non-referentially transparent modality, similar to but significantly weaker than the epistemic modalities, and to accept the corollary that imaginary (indeed—even impossible) threats can have real consequences that adversely affect online security. An apparently paradoxical outcome is that the desire of principals to keep their trust assumptions private can actually assist the design of systems to satisfy multiple security agendas. However, this approach requires agents to have the capability to predicate accurately about states of affairs that are logically inconsistent with their beliefs, and consequently, designing systems in this way becomes more akin to diplomacy than engineering.

Trust Management Scheme Based on D-S Evidence Theory for Wireless Sensor Networks

Trust management scheme has been regarded as a powerful tool to defend against the wide set of security attacks and identify malicious nodes. In this paper, we propose a trust management scheme based on revised Dempster-Shafer (D-S) evidence theory. D-S theory is preponderant in tackling both random and subjective uncertainty in the trust mechanism. A trust propagation mechanism including conditional trust transitivity and dynamic recommendation aggregation is developed for obtaining the recommended trust values from third part nodes. We adopt a flexible synthesis method that uses recommended trust only when no direct trust exists to keep a good trust-energy consumption balance. We also consider on-off attack and bad mouthing attack in our simulation. The simulation results and analysis show that the proposed method has excellent ability to deal with typical network attacks, better security, and longer network lifetime.

Enhancing the Trust of Internet Routing With Lightweight Route Attestation

The weak trust model in Border Gateway Protocol (BGP) introduces severe vulnerabilities for Internet routing including active malicious attacks and unintended misconfigurations. Although various secure BGP solutions have been proposed, the complexity of security enforcement and data-plane attacks still remain open problems. We propose TBGP, a trusted BGP scheme aiming to achieve high authenticity of Internet routing with a simple and lightweight attestation mechanism. TBGP introduces a set of route update and withdrawal rules that, if correctly enforced by each router, can guarantee the authenticity and integrity of route information that is announced to other routers in the Internet. To verify this enforcement, an attestation service running on each router provides interfaces for a neighboring router to challenge the integrity of its routing stack, enforced rules, and the attestation service itself. If this attestation succeeds, the neighboring router updates its routing table or announces the route to its neighbors, following the same rules. Thus, a router on a routing path only needs to verify one neighbor's routing status to ensure that the route information is valid. Through this, TBGP builds a transitive trust relationship among all routers on a routing path. We implement a prototype of TBGP to investigate its practicality. In our implementation, we use identity-based signature and trusted computing techniques to further reduce the complexity of security operations. Our security analysis and performance study shows that TBGP can achieve the security goals of BGP with significantly better convergence performance and lower computation overhead than existing secure BGP solutions.

Analysis of Trust Chain Transitivity in TCG

Trust chain is fundamental technology of Trusted Computing facing many problems. This paper points out that trust chain is made of two stages, analyses different trust relation building mechanism of two stages, and also thinks and proves that trust loss during trust transitivity process comes from composition loss and so on, describes behavior of trust chain transitivity quantitatively. After discussing key factors affect the trust, this paper defines the general trust transitivity model and trust loss measurement function, and discusses trust loss of Stage1 in TCG.

Pruning trust–distrust network via reliability and risk estimates for quality recommendations

The efficacy of trust links from social networks in boosting the user inter-connectivity in an otherwise poorly connected user group, obtained from historical preference data, has recently led to adoption of systems exploiting both these information sources to discover user proximities for recommender systems (RS). However, the investigation into the utility of distrust in the recommendation process is in its infancy. We propose a collaborative filtering framework based on computing user trust by exploiting functional and referral trust and distrust information together with user preference data. The inclusion of multiple sources of opinions for computing trust results in improved coverage and the trust network so formed can be used to infer indirect trust between entities by exploiting transitivity of trust. We also quantify the risk in relying on trust statements as a function of knowledge contained in the statement and the conflict in opinions about an entity and argue that pruning the trust graph by discarding risky and retaining reliable trust statements results in more accurate and robust recommendations while not compromising on the coverage. The experimental results corroborate our ideas and outperform several baseline algorithms.

Mitigating Risks Associated with Transitive Trust in Service-Based Identity Propagation

ABSTRACT Over the past 20 years, software has evolved from monolithic, stove-piped applications to services that communicate with other distributed components over communications networks. The rise in popularity of Service-oriented Architecture (SOA) and web services has presented unique challenges for securely conveying the identity of end users at every point, especially when mashups, Web service composition and orchestration solutions combine multiple distributed components throughout a network, and where each component may need to know the identity of the end user. Over the past decade, many U.S. government projects have embraced SOA, have identified security risks with certain types of identity propagation, and have built solutions for mitigating the risks. This paper focuses on identity propagation in Web service transactions and describes how several early SOA-based projects utilized “transitive trust” approaches. We categorize the security risks found and describe how these projects minimized or mitigated the risks. Finally, we discuss approaches used in current projects and provide guidance for future implementations.

Trust Transitivity in Complex Social Networks

In Online Social Networks (OSNs), participants can conduct rich activities, where trust is one of the most important factors for their decision making. This necessitates the evaluation of the trustworthiness between two unknown participants along the social trust paths between them based on the trust transitivity properties (i.e., if A trusts B and B trusts C, then A can trust C to some extent). In order to compute more reasonable trust value between two unknown participants, a critical and challenging problem is to make clear how and to what extent trust is transitive along a social trust path. To address this problem, we first propose a new complex social network structure that takes, besides trust, social relationships, recommendation roles and preference similarity between participants into account. These factors have significant influence on trust transitivity. We then propose a general concept, called Quality of Trust Transitivity (QoTT), that takes any factor with impact on trust transitivity as an attribute to illustrate the ability of a trust path to guarantee a certain level of quality in trust transitivity. Finally, we propose a novel Multiple QoTT Constrained Trust Transitivity (MQCTT) model. The results of our experiments demonstrate that our proposed MQCTT model follows the properties of trust and the principles illustrated in social psychology, and thus can compute more resonable trust values than existing methods that consider neither the impact of social aspects nor the properties of trust.

Trust Transitivity in Social Networks

Non-centralized recommendation-based decision making is a central feature of several social and technological processes, such as market dynamics, peer-to-peer file-sharing and the web of trust of digital certification. We investigate the properties of trust propagation on networks, based on a simple metric of trust transitivity. We investigate analytically the percolation properties of trust transitivity in random networks with arbitrary in/out-degree distributions, and compare with numerical realizations. We find that the existence of a non-zero fraction of absolute trust (i.e. entirely confident trust) is a requirement for the viability of global trust propagation in large systems: The average pair-wise trust is marked by a discontinuous transition at a specific fraction of absolute trust, below which it vanishes. Furthermore, we perform an extensive analysis of the Pretty Good Privacy (PGP) web of trust, in view of the concepts introduced. We compare different scenarios of trust distribution: community- and authority-centered. We find that these scenarios lead to sharply different patterns of trust propagation, due to the segregation of authority hubs and densely-connected communities. While the authority-centered scenario is more efficient, and leads to higher average trust values, it favours weakly-connected “fringe” nodes, which are directly trusted by authorities. The community-centered scheme, on the other hand, favours nodes with intermediate in/out-degrees, in detriment of the authorities and its “fringe” peers.

Measurement of Trust Transitivity in Trustworthy Networks

In this paper, we abstract the trust network as a weighted digraph. A path from node A to node B represents a transitive trust relationship. Parallel paths between a source and a target are associated with parallel trusts respectively. We introduce two measurements for computing the derived trust degree from a source to a target: Max- min trust degree and Max-mean trust degree. The Max operator formalizes the choice among parallel paths. The min and mean operators compute the transitive trust degree along a path. We focus on the analysis of the complexity of computing both kinds of trust degrees. We show that measuring the max-min trust degree is polynomial, however, measuring the max-mean one is NP-hard. Then we propose a matrix-based method to compute the max-mean trust degree, which can be done polynomially, but may produce non-simple paths. Finally, we give a simple example of a trust reputation network to illustrate the matrix-based method.

A Trust Transitivity Model Based-on Dempster-Shafer Theory

With the expansion of the Internet, Trust has attracted the attention of more and more researchers. This paper focuses on the trust transitivity problem and proposes a trust transitivity model based on Dempster-Shafer Theory. In our model, we show two types of trust relationship: Identity Trust and Behavior Trust based on Directness Trust and Recommendation Trust. Then we build the trust transitivity network and propose the trustworthiness propagation and combination rules. Finally, we propose a method for transforming the triple of evidence theory to a simple result in order to select the trust entity easily. W e also use the nearness degree to analyze the transitivity rationality and show how to use the trust transitivity model by a shopping scenario in TaoBao and illustrate its legitimacy

Analysing Trust Transitivity and the Effects of Unknown Dependence

Trust can be used to improve online automated recommendation within a given domain. Trust transitivity is used to make it successful. But trust transitivity has different interpretations. Trust and trust transitivity; both are the human mental phenomenon and for this reason, there is no such thing as objective transitivity. Trust transitivity and trust fusion both are important elements in computational trust. This paper analyses the parameter dependence problem in trust transitivity and proposes some definitions considering the effects of base rate. In addition, it also proposes belief functions based on subjective logic to analyse trust transitivity of three specified cases with sensitive and insensitive based rate. Then it presents a quantitative analysis of the effects of unknown dependence problem in an interconnected network environment; such Internet.