Abstract of /TIGKI/INFOSYS/FKI/FKI-247-03

Document-Name:  fki-247-03.ps.gz
Title:		Private Public Choice
Authors:	Felix Brandt 
Revision-Date:	M?rz 2003
Category:	Technical Report (Forschungsberichte Künstliche Intelligenz)
Abstract:	The fields of social choice theory and mechanism design deal with the
		aggregation of conflicting preferences in a group of agents, may they be
		electronic or human. Two central problems in these areas are the
		\emph{social choice problem} and the \emph{mechanism design problem}. We argue
		that the protection of individual preferences has not been considered so far
		and introduce the \emph{preference protection problem}, which we aim to solve
		by applying a fruitful subfield of cryptography called secure multiparty
		computation. Similar to the implementation of social choice functions in
		mechanisms, our new view on public choice adds another level to the model by
		introducing the emulation of mechanisms by cryptographic protocols. This
		enables the private and secure execution of mechanisms without trusted
		third-parties by distributing the computation of the mechanism outcome on the
		participating agents. It is shown that security against computationally bounded
		adversaries is possible whereas general mechanisms can not be emulated by
		protocols that are secure against unbounded adversaries. We then investigate
		how to construct efficient special-purpose protocols, such as a protocol that
		emulates the Clarke tax mechanism.
Keywords:	agents, mechanism design, social choice, cryptography, Clarke tax, MPC
Size:		11 pages
Language:	English
ISSN:		0941-6358
Copyright:	The ``Forschungsberichte Künstliche Intelligenz''
		series includes primarily preliminary publications,
		specialized partial results, and supplementary
		material. In the interest of a subsequent final
		publication these reports should not be copied. All
		rights and the responsibility for the contents of the
		report are with the authors, who would appreciate
		critical comments.

Matthias Nickles