Gesellschaft für Informatik e.V.

Lecture Notes in Informatics


INFORMATIK 2007 Informatik trifft Logistik Band 2 Beiträge der 37. Jahrestagung der Gesellschaft für Informatik e.V. (GI) 24. - 27. September 2007 in Bremen P-110, 184-188 (2007).

Gesellschaft für Informatik, Bonn
2007


Editors

Otthein Herzog (ed.), Karl-Heinz Rödiger (ed.), Marc Ronthaler (ed.), Rainer Koschke (ed.)


Copyright © Gesellschaft für Informatik, Bonn

Contents

A non-sequential unsplittable privacy-protecting multi-coupon scheme

H. Löhr , A. -R Sadeghi and A. N. Escalante B.

Abstract


A multi-coupon (MC ) represents a collection of k coupons that a user can redeem to a vendor in exchange for a benefit (some good or service). Recently, Chen et al. [CEL+07] proposed an unforgeable privacy-protecting multi-coupon scheme (MCS ), which discourages sharing of coupons through a property called unsplittability, where the coupons of a single MC cannot be separately used by two users. Previous MCS s relied on the all-or-nothing principle, a weaker form of unsplittability, where sharing a single coupon implies sharing the whole multi-coupon. The construction proposed in [CEL+07] supports coupons with practical attributes: independent benefits, and validity periods (e.g., expiration dates). However, it has the disadvantage that the coupons contained in an MC must be redeemed in sequential order. Hence, it is suitable for fewer applications. In this paper, we address this problem and propose a scheme that satisfies the same set of security requirements, supports the same practical attributes, and offers similar efficiency, but in which users are able to choose which coupon they redeem.


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Gesellschaft für Informatik, Bonn
ISBN 978-3-88579-206-1


Last changed 04.10.2013 18:14:58