4 research outputs found
Privacy-Enhancing First-Price Auctions Using Rational Cryptography
We consider enhancing a sealed-bid single-item auction with
\emph{privacy} concerns, our assumption being that bidders primarily
care about monetary payoff and secondarily worry about exposing
information about their type to other players and learning information
about other players\u27 types. To treat privacy explicitly within the
game theoretic context, we put forward a novel \emph{hybrid utility}
model that considers both fiscal and privacy components in the
players\u27 payoffs.
We show how to use rational cryptography to approximately implement a
given \emph{ex interim} individually strictly rational equilibrium of
such an auction (or any game with a winner) without a trusted mediator
through a cryptographic protocol that uses only point-to-point
authenticated channels between the players. By ``ex interim
individually strictly rational\u27\u27 we mean that, given its type and
before making its move, each player has a strictly positive expected
utility, i.e., it becomes the winner of the auction with positive
probability. By ``approximately implement\u27\u27 we mean that, under
cryptographic assumptions, running the protocol is a computational
Nash equilibrium with a payoff profile negligibly close to the
original equilibrium.
In addition the protocol has the stronger property that no collusion,
of any size, can obtain more by deviating in the implementation than
by deviating in the ideal mediated setting which the mechanism was
designed in. Also, despite the non-symmetric payoffs profile, the
protocol always correctly terminates
Opportunistic Sensing: Security Challenges for the New Paradigm
We study the security challenges that arise in Opportunistic people-centric sensing, a new sensing paradigm leveraging humans as part of the sensing infrastructure. Most prior sensor-network research has focused on collecting and processing environmental data using a static topology and an application-aware infrastructure, whereas opportunistic sensing involves collecting, storing, processing and fusing large volumes of data related to everyday human activities. This highly dynamic and mobile setting, where humans are the central focus, presents new challenges for information security, because data originates from sensors carried by people— not tiny sensors thrown in the forest or attached to animals. In this paper we aim to instigate discussion of this critical issue, because opportunistic people-centric sensing will never succeed without adequate provisions for security and privacy. To that end, we outline several important challenges and suggest general solutions that hold promise in this new sensing paradigm