Design of a fair proxy raffle protocol on the Internet Yu-Yi Chen a , Jinn-Ke Jan b, * , Chin-Ling Chen c a Department of International Business, Providence University, Taichung, Taiwan, ROC b Institute of Computer Science, National Chung Hsing University, Taichung, Taiwan, ROC c Institute of Applied Mathematics, National Chung Hsing University, Taichung, Taiwan, ROC Received 11 May 2004; received in revised form 9 November 2004; accepted 9 November 2004 Available online 13 December 2004 Abstract We proposed a practical, anonymous, and publicly verifiable raffle protocol for use on the Internet. This method integrates cryptology such as public key infrastructure, hashing chain, and blind signature et al. We also involve a trust proxy center to coordinate the raffle. The winning number generation is publicly verifiable. All of the participant’s raffle tickets must be involved with each one having an equal chance to win the prize. This will give the raffle higher credibility and practicability. Most importantly our scheme can be easily implemented on the Internet. The proposed method will be very useful for network marketing. D 2004 Elsevier B.V. All rights reserved. Keywords: Lottery; Raffle; Fairness; Anonymity; Internet 1. Introduction Promotion and advertising can be a heavy expense. Smart business people know that it costs more time and money to win over new customers than to keep current customers. Keeping current customers loyal produces more profits from repeat purchases in the long run. The most familiar, low-cost sales promotion is offering a raffle draw upon purchase. As we know, many merchants hold attractive raffles at their annual celebrations. Customers must accumulate a certain number of purchases in exchange for a raffle ticket to encourage purchases. As usual, the prizes must be large, ranging from electronic gadgets to vacation trips. The size and number of prize depend entirely on the raffle period length, the number of raffle tickets to be issued, and how much money is spent on the prizes. This is an extremely powerful method to excite consumer desire to purchase product. With the prosperous growth of the Internet, more enterprises are paying much attention to network marketing. At the present time, how to implement a fair and secure raffle drawing technology on the Internet has still not been proposed. We reviewed 0920-5489/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.csi.2004.11.002 * Corresponding author. Tel.: +886 4 22858200. E-mail addresses: yuyichen@pu.edu.tw (Y.-Y. Chen)8 jkjan@cs.nchu.edu.tw (J.-K. Jan)8 sd64cgli@cht.com.tw (C.-L. Chen). Computer Standards & Interfaces 27 (2005) 415 – 422 www.elsevier.com/locate/csi