Rehab Alnemr

Distributed Trust Management for Validating SLA Choreographies

For business workflow automation in a service-enriched environment such as a grid or a cloud, services scattered across heterogeneous Virtual Organizations (VOs) can be aggregated in a producer-consumer manner, building hierarchical structures of added value. In order to preserve the supply chain, the Service Level Agreements (SLAs) corresponding to the underlying choreography of services should also be incrementally aggregated. This cross-VO hierarchical SLA aggregation requires validation, for which a distributed trust system becomes a prerequisite. Elaborating our previous work on rule-based SLA validation, we propose a hybrid distributed trust model. This new model is based on Public Key Infrastructure (PKI) and reputation-based trust systems. It helps preventing SLA violations by identifying violation-prone services at service selection stage and actively contributes in breach management at the time of penalty enforcement.

Enabling usage control through reputation objects: a discussion on e-commerce and the internet of services environments

This paper discusses the meaning and the role of Trust and Reputation in Internet-of-Service and e-Commerce environments following a comparative case study. Both environments represent paradigms through which the Internet is seen as a huge infrastructure where electronic services or real products are traded on. In comparison to electronic commerce, participating in an Internet-of-Services can be full of risks for all participants. Even well known security mechanisms are not able to close all gaps of access and usage control. This paper discusses the concepts of trust and reputation and brings to light the relation between these concepts to security mechanisms, Service-Level-Agreements, and quality measurements in order to enable Usage Control. The proposed solution is based on our previous model of reputation objects. The discussion also introduces a new concept of what we call reputation auditing where quality processes are considered part of reputation management not the other way around.

Getting More from Reputation Systems: A ContextAware Reputation Framework Based on Trust Centers and Agent Lists

Reputation is a crucial factor in trust and thus in Web communities. Trust strategies may involve investigating user reputation or directly using transitive reputation to form the Web of Trust. We suggest an approach that takes advantage of both strategies without increasing the cost of investigation. Several systems nowadays form what we call ldquouser Web communitiesrdquo. In these communities, reputation related to different contexts needs to be exchanged. The perception, calculation and interpretation of this reputation differ from one community to another. We propose the development of reference models to diminish the distance between these multi-perceptions. We also propose the use of reputation centers to facilitate reputation transfer and highlight the importance of their role in analyzing attacks on reputation.

Constructing a Context-Aware Service-Oriented Reputation Model Using Attention Allocation Points

In this paper we examine the problem of rich information environments and the need to narrow the agents attention to what is important for them to interact and later to evaluate and transfer reputation values, using Attention Allocation technique (AA). We also argue that this cannot be done without the aid of Service Oriented Architecture (SOA). Reputation is used in our work as a service, presenting a new concept- that is Reputation-as-a-Service (RaaS). We then present a service-oriented model for optimizing the presentation and the use of reputation in order to maximize its value to both users and providers.

A security and high-availability layer for cloud storage

Cloud Computing as a service on demand architecture has become a topic of interest in the last few years. The outsourcing of duties and infrastructure to external parties enables new services to be established quickly, scaled on demand, and with low financial risk. Cloud storage enables organizations to manage their data with low operational expenses. Nevertheless, several issues such as security and the risk to become dependent on a provider for its service should be considered before entering the cloud. In general, a switch of a storage provider is associated with high costs of adapting new APIs and additional charges for inbound and outbound bandwidth and requests. In this paper we use the principle of RAID-technology in cloud infrastructure to manage data distribution across cloud storage providers. The distribution is based on users expectations regarding providers geographic location, quality of service, providers reputation, and budget preferences. Our approach allows users to avoid vendor lock-in, reduce cost of switching providers and increase security and availability of their data. We also explain on how the proposed system removes the complexity of interacting with multiple storage providers while maintaining security.

Enabling reputation interoperability through semantic technologies

Reputation is a complex concept that has a major role in fields like social sciences, economics as well as computer science. Representing it as a simple form of property-rating or a vector of ratings strips it from its original notion and postulation. It does not also facilitate the derivation of meaningful conclusions from it. This paper presents a semantic model for the representation of reputation as a complex object - a so called Reputation Object (RO). We also argue that using ontologies, and other semantic web technologies, to represent the reputation object model is essential to achieve reputation interoperability and portability between different domains. The contribution is a semantic design artifact for reputation representation that agrees with the theoretical and social formation and processing of reputation information. We also show some applications and how this ontology-based reputation model can be applied in a rule-based open reputation system. The work presented here has significant implications for e-market studies of knowledge sharing.

Towards Semantic Event-Driven Systems

One of the critical success factors of event-driven systems is the capability of detecting complex events from simple and ordinary event notifications. Complex events which trigger or terminate actionable situations can be inferred from large event clouds or event streams based on their event instance sequence, their syntax and semantics. Using semantics of event algebra patterns defined on top of event instance sequences for event detection is one of the promising approaches for detection of complex events. The developments and successes in building standards and tools for semantic technologies such as declarative rules and ontologies are opening novel research and application areas in event processing. One of these promising application areas is semantic event processing. In this paper we contribute with a conceptual approach which supports the implementation of the vision of semantic event-driven systems; using Semantic Web technologies, benefiting from complex event processing, and ensuring quality through trust and reputation management. All of these novel technologies leads to more intelligent decision supporting systems.

From Reputation Models and Systems to Reputation Ontologies

Reputation has been explored in diverse disciplines such as artificial intelligence, electronic commerce, peer-to-peer network, and multi-agent systems. Recently it has been a vital component for ensuring trust in web services and service oriented architectures domains. Although there are several studies on reputation systems as well as reputation models, there is no study that covers reputation ontologies especially the ones implemented using standardized frameworks like semantic technologies. In this paper, we show the evolution towards reputation ontologies and investigate existing ones in the domains of multi-agent systems, web services, and online markets. We define the requirements for developing a reputation ontology and use them to analyze some of the existing ontologies. The components and functionalities of reputation models and systems are described briefly and the importance of developing and using reputation ontologies is highlighted within the emergence of the Semantic Web and Semantic Web services.

Towards Context-Aware Service-Oriented Semantic Reputation Framework

Reputation has been explored in diverse disciplines such as artificial intelligence, electronic commerce, peer-to-peer network, and multi-agent systems. Recently it has been a vital component for ensuring trust in web services and service oriented architecture domains. In this paper, we show details about our context-aware reputation framework. The framework is based on our semantic representation model for reputation called Reputation Object (RO) model. We discuss the advantages and propositions to construct such framework, its components, and how it is implemented. The importance of developing and using such generic reputation framework is highlighted within the emergence of the Semantic Web and service oriented architecture.

Trend-based and reputation-versed personalized news network

Web users while collaborating over social networks and micro-blogging services also contribute to news coverage worldwide. News feeds come from mainstream media as well as from social networks. Often feeds from social networks are more up-to-date and, for users view, more credible than those that come from mainstream media. But the overwhelming amount of information requires to personally filter through it until one gets what is really needed. In this paper, we describe our idea of a personalized news network built on current Web technologies and our research projects by filtering Twitter and Facebook messages using both trend mining and reputation approaches. Based on the example of Egyptian revolution, we explain the main idea of personalized news.