Security Enforcement And Query Routing On Privacy Preserving Information Brokering System

Nowadays in organizations information sharing has been increased via on-demand access. Information brokering systems (IBSs) have been proposed to connect large-scale loosely federated data sources via a brokering overlay, in which the brokers make routing decisions to direct client queries to the requested data servers. Some of existing IBSs assume that brokers are trusted and thus only adopt server-side access control for data confidentiality. However, privacy of data location and data consumer can still be inferred from metadata (such as query and access control rules) exchanged within the IBS, but little attention has been put on its protection. With this the privacy concerns arise, as brokers are no longer assumed fully trustable – they may be abused by insiders or compromised by outsiders. For overcoming this, a novel IBS, named Privacy Preserving Information Brokering (PPIB) has been proposed. In this paper, we propose a novel approach to preserve privacy of multiple stakeholders involved in the information brokering process. PPIB has three components: brokers, coordinators and central authority. We are among the first to formally define two privacy attacks, namely attribute-correlation attack and inference attack, and propose two countermeasure schemes automaton segmentation and query segment encryption to securely share the routing decision-making responsibility among a selected set of brokering servers. The PPIB scheme is improved by supporting site distribution and load balancing mechanism. Workloads of peers and each peer’s trust levels are integrated with the site distribution process. With the comprehensive analysis on scalable privacy and load balancing we show that the propose system can integrate security enforcement and query routing while preserving system wide privacy.