IJSRST1622113 | Received: 20 April 2016 | Accepted: 26 April 2016 | March-April 2016 [(2)2: 210-217] © 2016 IJSRST | Volume 2 | Issue 2 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X Themed Section: Science and Technology 210 Secure and Trusted Information Brokering In Cloud Computing Jayalakshmi Kanagasabapathy * , C. Swaraj Paul Department of Computer Science and Engineering, Vels University, Chennai, Tamil Nadu, India ABSTRACT To facilitate extensive collaborations, today’s organizations raise increasing needs for information sharing via on - demand information access. Information Brokering System (IBS) a top a peer-to-peer overlay has been proposed to support information sharing among loosely federated data sources. It consists of diverse data servers and brokering components, which help client queries to locate the data servers. However, many existing IBSs adopt server side access control deployment and honest assumptions on brokers, and shed little attention on privacy of data and metadata stored and exchanged within the IBS. In this article, we study the problem of privacy protection in information brokering process. We first give a formal presentation of the threat models with a focus on two attacks: attribute-correlation attack and inference attack. Then, we propose a broker-coordinator overlay, as well as two schemes, automaton segmentation scheme and query segment encryption scheme, to share the secure query routing function among a set of brokering servers. With comprehensive analysis on privacy, end to- end performance, and scalability, we show that the proposed system can integrate security enforcement and query routing while preserving system-wide privacy with reasonable overhead. Finally, T-broker uses a lightweight feedback mechanism, which can effectively reduce networking risk and improve system efficiency. The experimental results show that, compared with the existing approaches, our T-broker yields very good results in many typical cases, and the proposed system is robust to deal with various numbers of dynamic service behavior from multiple cloud sites. Keywords: Information Broking System, Automation segmentation, coordinates broker, privacy preserving, and Attribute-correlation attack I. INTRODUCTION In recent years, we have observed an explosion of information shared among organizations in many realms ranging from business to government agencies. To facilitate efficient large-scale information sharing, many efforts have been devoted to reconcile data heterogeneity and provide interoperability across geographically distributed data sources. In the context of sensitive data and autonomous data owners, a more practical and adaptable solution is to construct a data centric overlay including the data sources and a set of brokers helping to locate data sources for queries Such infrastructure builds up semantic-aware index mechanisms to route the queries based on their content, which allows users to submit queries without knowing data or server location. In our previous study, such a distributed system providing data access through a set of brokers is referred to as Information Brokering System (IBS). Figure 1: An overview of the IBS infrastructure. While the IBS approach provides scalability and server autonomy, privacy concerns arise, as brokers are no