UNIVERSITY OF HERTFORDSHIRE
		 COMPUTER SCIENCE RESEARCH COLLOQUIUM

			      presents

		  "Extending Trust in Cyberspace"

			   Stephen Clarke
	    (Algorithms Research Group, School of Computer
		Science, University of Hertfordshire)

		    20 February 2008 (Wednesday)

			Lecture Theatre E350
		     Hatfield, College Lane Campus
			     3 - 4 pm

	       Coffee/tea and biscuits will be available.

		    Everyone is Welcome to Attend


Abstract:


The need for good online trust relationships is ever more prominent
with the increase of online services over the last decade. Transactions
between initially unknown principals are more common since the rise of
auction and marketplace websites such as eBay and Amazon. Trust is also
required for non-physical transactions such as file transfers or
accessing computer/network resources for example.

Reputation systems are the most commonly employed method of quantifying
trust in environments where it is needed. For example, eBay has a
feedback forum where its users can see a history of comments to aid
them in deciding who to trade with. The problem that all reputation
systems share (and other solutions) is that they imply that trust is
transitive. Transitivity is undesirable as it assumes that you trust
people you don't know and therefore doesn't fully solve the issue.

In this talk, the notion of extending trust using an electronic
equivalent of a guarantee will be discussed. Electronic guarantees need
to underwrite the risk and localise the trust in the same way that real
world guarantees do. I'll give examples of how this idea works and how
it uses delegation in order to avoid requiring transitivity of trust. A
novel approach to implementing these guarantees by using a combination
of trust management techniques and micropayment schemes will be
demonstrated. Finally, the next stages of this research will be
discussed.


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Hertfordshire Computer Science Research Colloquium
http://homepages.feis.herts.ac.uk/~nehaniv/colloq