Project Name – The three-tier security scheme in wireless sensor networks with mobile sinks
Mobile sinks (MSs) are vital in many wireless sensor network (WSN) applications for efficient data accumulation, localized sensor reprogramming, and for distinguishing and revoking compromised sensors. However, in sensor networks that make use of the existing key redistribution schemes for pair wise key establishment and authentication between sensor nodes and mobile sinks, the employment of mobile sinks for data collection elevates a new security challenge: in the basic probabilistic and q-composite key pre-distribution schemes, an attacker can easily obtain a large number of keys by capturing a small fraction of nodes, and hence, can gain control of the network by deploying a replicated mobile sink preloaded with some compromised keys. This article describes a three-tier general framework that permits the use of any pairwise key predistribution scheme as its basic component. The new framework requires two separate key pools, one for the mobile sink to access the network, and one for pairwise key establishment between the sensors. To further reduce the damages caused by stationary access node replication attacks, we have strengthened the authentication mechanism between the sensor and the stationary access node in the proposed framework. Through detailed analysis, we show that our security framework has higher network resilience to a mobile sink replication attack as compared to the polynomial pool-based scheme.
Project Name – Bootstrapping ontologies for web services
Ontological bootstrapping which aims at automatically generating concepts and their relations in a given domain is a promising technique for ontology construction. Bootstrapping an ontology based on a set of predefined textual sources, such as Web services, must address the problem of multiple, largely unrelated concepts.
Abstract : The ontology bootstrapping process is based on analyzing a Web service using three different methods, where each method represents a different perspective of viewing the Web service. As a result, the process provides a more accurate definition of the ontology and yields better results. In particular, the Term Frequency/ Inverse Document Frequency (TF/IDF) method analyzes the Web service from an internal point of view, i.e., what concept in the text best describes the WSDL document content. The Web Context Extraction method describes the WSDL document from an external point of view, i.e., what most common concept represents the answers to the Web search queries based on the WSDL content. Finally, the Free Text Description Verification method is used to resolve inconsistencies with the current ontology.
Project Name – Privacy and integrity-preserving range queries in sensor networks
The architecture of two-tiered sensor networks, where storage nodes serve as an intermediate tier between sensors and a sink for storing data and processing queries, has been widely adopted because of the benefits of power and storage saving for sensors as well as the efficiency of query processing. However, the importance of storage nodes also makes them attractive to attackers. SafeQ, a protocol is proposed, that prevents attackers from gaining information from both sensor collected data and sink issued queries. SafeQ also allows a sink to detect compromised storage nodes when they misbehave. To preserve privacy, SafeQ uses a novel technique to encode both data and queries such that a storage node can correctly process encoded queries over encoded data without knowing their values. To preserve integrity, two schemes has been proposed, one using Merkle hash trees and another using a new data structure called neighborhood chains, to generate integrity verification information so that a sink can use this information to verify whether the result of a query contains exactly the data items that satisfy the query.