Catálogo de publicaciones - libros

WAND is a P2P meta-data management system providing a file-system tree interface. Users are able to share files on the global file-system tree. The file system tree is robust and maintains its structure even when nodes enter and leave the network. The key ideas that make the file-system tree robust are a concept of and a novel algorithm to handle network partitioning.

This paper deals with a Tsunami warning system based on distributed sensor networks employing level controlled gossip. Level controlled gossip is a technique that is being proposed which employs leveling and gossiping together. The technique reduces the number of messages by transmitting messages in direction of base station only and there by increases the life-time of wireless sensor network. By using various power levels at base station the sensor field is hierarchically partitioned into levels of increasing radius (containing various sensor nodes). The algorithm divides the entire sensor network into logical con-centric zones based on proximity from the base station, whereby the packet is transmitted from a node of higher depth to nodes in the next zone with lesser depth. The transmission probability increases with the proximity of the Tsunami wave to the base station. The primary advantage of the protocol is transmitting a critical event with higher probability and at the same time conserving lifetime of the network for future monitoring.

Ontological concept Relation extraction is a difficult research problem. In this paper, we aim to extract multi-type relations from the text analyses and the existent relations (in the concept hierarchy). Our approach combines a verb centered method, lexical analyses, syntactic and statistic ones. It is based on a rich contextual modeling that strengthens the term co-occurrence selection, a lexical analysis, a use of the existent relations in the concept hierarchy and a stepping between the extracted relations to validate them and facilitate the evaluation made by the domain experts.

This paper devises a new e-commerce protocol that can ensure fair exchange and customer’s anonymity for digital content transactions. The proposed protocol considers the complete transaction process: negotiating, withdrawing, purchasing, and arbitrating phases. The offline arbitrator reduces the possibility of becoming a bottleneck. By scrupulous analysis, the proposed protocol achieves fair exchange, customer’s anonymity, and good efficiency.

People are concerned with spam mails and viruses or worms contained in e-mails. However, people often neglect the security issues concerning the content of e-mails. In this paper, we propose practical and secure e-mail protocols that provide perfect forward secrecy. Unlike previous proposals, our protocols can be deployed without any change to the current infrastructure. Moreover, we provide a way for the sender to securely send an identical e-mail to multiple receivers.

We propose a framework for secure and trusted business to business (B2B) collaborations over grid. The core of the proposal consists of a centralised rating system for assignment and maintenance of trust and reputation scores of enterprises.We also propose augmentations to the Globus Toolkit 4 (GT4) [8] for implementing the proposed rating system. It involves integration of three functionalities, namely, (i) building a suitable token structure according to the model of a security token, (ii) building and deploying a trust service which keeps track of the ratings of the collaborating business entities, and (iii) building an information aggregator source which provides these ratings and related information from the trust service to the GT4 default index service.