A Privacy-Protecting Coupon System

A coupon represents the right to claim some service which is typically offered by vendors. In practice, issuing bundled multi-coupons is more efficient than issuing single coupons separately. The diversity of interests of the parties involved in a coupon system demands additional security properties beyond the common requirements (e.g., unforgeability). Customers wish to preserve their privacy when using the multi-coupon bundle and to prevent vendors from profiling. Vendors are interested in establishing a long-term customer relationship and not to subsidise one-time customers, since coupons are cheaper than the regular price. We propose a secure multi-coupon system that allows users to redeem a predefined number of single coupons from the same multi-coupon. The system provides unlinkability and also hides the number of remaining coupons of a multi-coupon from the vendor. In the coupon system, a method used might be of independent interest. It proves knowledge of a signature on a me...

• Type: Conference
• Year: 2005
• Where: FC
• Authors: Liqun Chen, Matthias Enzmann, Ahmad-Reza Sadeghi, Markus Schneider 0002, Michael Steiner
• Keywords: Coupon, Demands Additional Security, FC 2005, Single Coupons