Protocol Completion Incentive Problems in Cryptographic Vickrey Auctions ∗ Phillip G. Bradford † Department of Computer Science The University of Alabama Box 870290 Tuscaloosa, AL 35487-0290 pgb@cs.ua.edu Sunju Park School of Business Yonsei University Seoul, Korea boxenju@yonsei.ac.kr Michael H. Rothkopf Management Science and Information Systems Department and Rutgers Center for Operations Research Rutgers University Piscataway, NJ 08854-8003 rothkopf@rutcor.rutgers.edu Heejin Park College of Information and Communications Hanyang University Seoul, Korea hjpark@hanyang.ac.kr November 8, 2007 * A preliminary version of this paper appeared in the proceedings of The Seventh International Conference on Electronic Commerce Research (ICECR-7), Bezalel Gavish–Technical Program Chair, 55-64, 2004. See http://rutcor.rutgers.edu/pub/rrr/reports2004/3 2004.pdf † Corresponding Author 1