Hitesh Tewari

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As business is moving from face-to-face trading, mail order, and telephone order to electronic commerce over open networks such as the Internet, crucial security issues are being raised. Whereas Electronic Funds Transfer over financial networks is reasonably secure, securing payments over open networks connecting commercial servers and consumer workstations(More)
Declaration I declare that the work described in this dissertation is, except where otherwise stated, entirely my own work and has not been submitted as an exercise for a degree at this or any other university. I agree that Trinity College Library may lend or copy this dissertation upon request. iii Acknowledgements I would like to thank my supervisor, Mr.(More)
The past few years have witnessed an explosive growth in the use of wireless mobile handheld devices as the enabling technology for accessing Internet-based services, as well as for personal communication needs in ad hoc networking environments. Most studies indicate that it is impossible to utilize strong cryptographic functions for implementing security(More)
A characterization of predicate encryption (PE) with support for homomorphic operations is presented and we describe the homomorphic properties of some existing PE constructions. Even for the special case of IBE, there are few known group-homomorphic cryptosystems. Our main construction is an XOR-homomorphic IBE scheme based on the quadratic residuosity(More)
—This paper introduces a new P2P Electronic Cash system called Netcoin. The purpose of Netcoin is to facilitate inexpensive peer-to-peer monetary transactions on the Web. Its salient features are that it is a traceable system with an efficient mechanism for verifying transactions. Netcoins are reusable and can be easily passed from one user to another. The(More)
Identity Based Encryption (IBE) has been constructed from bilinear pairings, lattices and quadratic residuosity. The latter is an attractive basis for an IBE owing to the fact that it is a well-understood hard problem from number theory. Cocks constructed the first such scheme, and subsequent improvements have been made to achieve anonymity and improve(More)
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