UNIVERSITY OF HERTFORDSHIRE

    COMPUTER SCIENCE RESEARCH COLLOQUIUM


		presents

  "How to Deceive Prying Eyes in the Electronic World"

		speaker:

	    Partha Das Chowdhury
       Computer Science Department
       University of Hertfordshire

     (joint work with Bruce Christianson)

	15  October 2003 (Wednesday)

	  Lecture Theatre E350
	    Hatfield Campus
		3 - 4 pm


 Coffee/tea and biscuits will be available.


      Everyone is Welcome to Attend


Abstract:

The usual assumption in non-anonymous protocols is that if our key is
stolen Mallory can do anything we can do with our key unless the use of
the key is bound to an unforgeable credential which Mallory couldn't
steal. But this assumption is no longer safe in the anonymous world as
using the same credential every time will enable an adversary to
correlate all our actions. We present a protocol for anonymous
commercial transactions on the internet which is based on Tal Rabin and
Ben Or's Information Checking. In our system we use unforgeable,
non-transferable payment tokens along with surrogates (ephemeral
electronic identities).  The surrogates have a common parent but their
use cannot be correlated to each other. Our protocol doesn't need any
non-trivial math and is information-theoretically secure.

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