Finding the optimal social trust path for the selection of trustworthy service providers in complex social networks

Online Social networks have provided the infrastructure for a number of emerging applications in recent years, e.g., for the recommendation of service providers or the recommendation of files as services. In these applications, trust is one of the most important factors in decision making by a service consumer, requiring the evaluation of the trustworthiness of a service provider along the social trust paths from a service consumer to the service provider. However, there are usually many social trust paths between two participants who are unknown to one another. In addition, some social information, such as social relationships between participants and the recommendation roles of participants, has significant influence on trust evaluation but has been neglected in existing studies of online social networks. Furthermore, it is a challenging problem to search the optimal social trust path that can yield the most trustworthy evaluation result and satisfy a service consumer's trust evaluation criteria based on social information. In this paper, we first present a novel complex social network structure incorporating trust, social relationships and recommendation roles, and introduce a new concept, Quality of Trust (QoT), containing the above social information as attributes. We then model the optimal social trust path selection problem with multiple end-to-end QoT constraints as a Multiconstrained Optimal Path (MCOP) selection problem, which is shown to be NP-Complete. To deal with this challenging problem, we propose a novel Multiple Foreseen Path-Based Heuristic algorithm MFPB-HOSTP for the Optimal Social Trust Path selection, where multiple backward local social trust paths (BLPs) are identified and concatenated with one Forward Local Path (FLP), forming multiple foreseen paths. Our strategy could not only help avoid failed feasibility estimation in path selection in certain cases, but also increase the chances of delivering a near-optimal solution with high quality. The results of our experiments conducted on a real data set of online social networks illustrate that MFPB-HOSTP algorithm can efficiently identify the social trust paths with better quality than our previously proposed H-OSTP algorithm that outperforms prior algorithms for the MCOP selection problem.16 page(s

Comparative Analysis of Privacy Preservation Mechanism: Assessing Trustworthy Cloud Services with a Hybrid Framework and Swarm Intelligence

Cloud computing has emerged as a prominent field in modern computational technology, offering diverse services and resources. However, it has also raised pressing concerns regarding data privacy and the trustworthiness of cloud service providers. Previous works have grappled with these challenges, but many have fallen short in providing comprehensive solutions. In this context, this research proposes a novel framework designed to address the issues of maintaining data privacy and fostering trust in cloud computing services. The primary objective of this work is to develop a robust and integrated solution that safeguards sensitive data and enhances trust in cloud service providers. The proposed architecture encompasses a series of key components, including data collection and preprocessing with k-anonymity, trust generation using the Firefly Algorithm, Ant Colony Optimization for task scheduling and resource allocation, hybrid framework integration, and privacy-preserving computation. The scientific contribution of this work lies in the integration of multiple optimization techniques, such as the Firefly Algorithm and Ant Colony Optimization, to select reliable cloud service providers while considering trust factors and task/resource allocation. Furthermore, the proposed framework ensures data privacy through k-anonymity compliance, dynamic resource allocation, and privacy-preserving computation techniques such as differential privacy and homomorphic encryption. The outcomes of this research provide a comprehensive solution to the complex challenges of data privacy and trust in cloud computing services. By combining these techniques into a hybrid framework, this work contributes to the advancement of secure and effective cloud-based operations, offering a substantial step forward in addressing the critical issues faced by organizations and individuals in an increasingly interconnected digital landscape

Quality of Information in Mobile Crowdsensing: Survey and Research Challenges

Smartphones have become the most pervasive devices in people's lives, and are clearly transforming the way we live and perceive technology. Today's smartphones benefit from almost ubiquitous Internet connectivity and come equipped with a plethora of inexpensive yet powerful embedded sensors, such as accelerometer, gyroscope, microphone, and camera. This unique combination has enabled revolutionary applications based on the mobile crowdsensing paradigm, such as real-time road traffic monitoring, air and noise pollution, crime control, and wildlife monitoring, just to name a few. Differently from prior sensing paradigms, humans are now the primary actors of the sensing process, since they become fundamental in retrieving reliable and up-to-date information about the event being monitored. As humans may behave unreliably or maliciously, assessing and guaranteeing Quality of Information (QoI) becomes more important than ever. In this paper, we provide a new framework for defining and enforcing the QoI in mobile crowdsensing, and analyze in depth the current state-of-the-art on the topic. We also outline novel research challenges, along with possible directions of future work.Comment: To appear in ACM Transactions on Sensor Networks (TOSN

A survey of QoS-aware web service composition techniques

Web service composition can be briefly described as the process of aggregating services with disparate functionalities into a new composite service in order to meet increasingly complex needs of users. Service composition process has been accurate on dealing with services having disparate functionalities, however, over the years the number of web services in particular that exhibit similar functionalities and varying Quality of Service (QoS) has significantly increased. As such, the problem becomes how to select appropriate web services such that the QoS of the resulting composite service is maximized or, in some cases, minimized. This constitutes an NP-hard problem as it is complicated and difficult to solve. In this paper, a discussion of concepts of web service composition and a holistic review of current service composition techniques proposed in literature is presented. Our review spans several publications in the field that can serve as a road map for future research

Trust aware system for social networks: A comprehensive survey

Social networks are the platform for the users to get connected with other social network users based on their interest and life styles. Existing social networks have millions of users and the data generated by them are huge and it is difficult to differentiate the real users and the fake users. Hence a trust worthy system is recommended for differentiating the real and fake users. Social networking enables users to send friend requests, upload photos and tag their friends and even suggest them the web links based on the interest of the users. The friends recommended, the photos tagged and web links suggested may be a malware or an untrusted activity. Users on social networks are authorised by providing the personal data. This personal raw data is available to all other users online and there is no protection or methods to secure this data from unknown users. Hence to provide a trustworthy system and to enable real users activities a review on different methods to achieve trustworthy social networking systems are examined in this paper

RECOMMENDING SERVICES IN A DIFFERNTIATED TRUST-BASED DECENTRALIZED USER MODELING SYSTEM

Trust and reputation mechanisms are often used in peer-to-peer networks, multi-agent systems and online communities for trust-based interactions among the users. Trust values are used to differentiate among members of the community as well as to recommend service providers. Although different users have different needs and expectations in different aspects of the service providers, traditional trust-based models do not use trust values on neighbors for judging different aspects of service providers. In this thesis, I use multi-faceted trust models for users connected in a network who are looking for suitable service providers according to their preferences. Each user has two sets of trust values: i) trust in different aspects of the quality of service providers, ii) trust in recommendations provided for these aspects. These trust models are used in a decentralized user modeling system where agents (representing users) have different preference weights in different criteria of service providers. My approach helps agents by recommending the best possible service provider for each agent according to its preferences. The approach is evaluated by conducting simulation on both small and large social networks. The results of the experiments illustrate that agents find better matches or more suitable service providers for themselves using my trust-based recommender system without the help of any central server. To the best of my knowledge this is the first system that uses multi-faceted trust values both in the qualities of service-providers and in other users’ ability to evaluate these qualities of service providers in a decentralized user modeling system

Partnership Development Among Mental Health Organizations

Mental health organizations can play a key role in enhancing youths\u27 access to care by working together to bridge gaps in service delivery systems. This dissertation study examines partnerships among a network of children\u27s behavioral health organizations. The specific aims are to (1) describe and understand the network of partnerships among members of the Children\u27s Services Coalition, (2) assess the capacity of the system to provide coordinated service delivery, and (3) test how patterns of organizational characteristics influence conditions that facilitate and inhibit partnerships among the Children\u27s Service Coalition organizations. This dissertation is a predominantly quantitative cross-sectional network study of 36 children\u27s mental health organizations in St. Louis County that are members of the newly formed Children\u27s Services Coalition. Network data on relationships and archival data from IRS 990 forms were collected and used to explain how organizational characteristics might lead certain organizations to partner, but create conditions that simultaneously facilitate and hinder the degree to which organizations partner. Overall, the key findings describe partnership behavior at the network, small-group, and dyadic-level. First, children\u27s behavioral health organizations in the CSC maintain a complex set of partnerships, which are expected to grow as new opportunities emerge. Second, although partnerships are very common, the larger network may not be well coordinated as evidenced by the few systematic partnership patterns uncovered using descriptive network analysis techniques including sub-group analysis and blockmodeling. However there is potential for coordination at the sub-group level among small groups of similar organizations. Finally, at the dyadic-level, results of a path analysis demonstrate how similar competing organizations depend on one another for resources and benefit from their collaboration, which drives partnerships. Results suggest that organizational interests drive partnership development in this network, and bring together competing organizations that provide similar resources potentially as a strategy for managing competition, or creating efficiencies. This trend runs counter to system reform goals for bridging organizations with complementary services to facilitate access to quality care

A MULTI-FUNCTIONAL PROVENANCE ARCHITECTURE: CHALLENGES AND SOLUTIONS

In service-oriented environments, services are put together in the form of a workflow with the aim of distributed problem solving. Capturing the execution details of the services' transformations is a significant advantage of using workflows. These execution details, referred to as provenance information, are usually traced automatically and stored in provenance stores. Provenance data contains the data recorded by a workflow engine during a workflow execution. It identifies what data is passed between services, which services are involved, and how results are eventually generated for particular sets of input values. Provenance information is of great importance and has found its way through areas in computer science such as: Bioinformatics, database, social, sensor networks, etc. Current exploitation and application of provenance data is very limited as provenance systems started being developed for specific applications. Thus, applying learning and knowledge discovery methods to provenance data can provide rich and useful information on workflows and services. Therefore, in this work, the challenges with workflows and services are studied to discover the possibilities and benefits of providing solutions by using provenance data. A multifunctional architecture is presented which addresses the workflow and service issues by exploiting provenance data. These challenges include workflow composition, abstract workflow selection, refinement, evaluation, and graph model extraction. The specific contribution of the proposed architecture is its novelty in providing a basis for taking advantage of the previous execution details of services and workflows along with artificial intelligence and knowledge management techniques to resolve the major challenges regarding workflows. The presented architecture is application-independent and could be deployed in any area. The requirements for such an architecture along with its building components are discussed. Furthermore, the responsibility of the components, related works and the implementation details of the architecture along with each component are presented

Privacy and trustworthiness management in moving object environments

The use of location-based services (LBS) (e.g., Intel\u27s Thing Finder) is expanding. Besides the traditional centralized location-based services, distributed ones are also emerging due to the development of Vehicular Ad-hoc Networks (VANETs), a dynamic network which allows vehicles to communicate with one another. Due to the nature of the need of tracking users\u27 locations, LBS have raised increasing concerns on users\u27 location privacy. Although many research has been carried out for users to submit their locations anonymously, the collected anonymous location data may still be mapped to individuals when the adversary has related background knowledge. To improve location privacy, in this dissertation, the problem of anonymizing the collected location datasets is addressed so that they can be published for public use without violating any privacy concerns. Specifically, a privacy-preserving trajectory publishing algorithm is proposed that preserves high data utility rate. Moreover, the scalability issue is tackled in the case the location datasets grows gigantically due to continuous data collection as well as increase of LBS users by developing a distributed version of our trajectory publishing algorithm which leveraging the MapReduce technique. As a consequence of users being anonymous, it becomes more challenging to evaluate the trustworthiness of messages disseminated by anonymous users. Existing research efforts are mainly focused on privacy-preserving authentication of users which helps in tracing malicious vehicles only after the damage is done. However, it is still not sufficient to prevent malicious behavior from happening in the case where attackers do not care whether they are caught later on. Therefore, it would be more effective to also evaluate the content of the message. In this dissertation, a novel information-oriented trustworthiness evaluation is presented which enables each individual user to evaluate the message content and make informed decisions --Abstract, page iii