This book constitutes the thoroughly refereed post-proceedings of the 8th International Conference on Financial Cryptography, FC 2004, held in Key West, FL, USA, in February 2004. talks and 4 panel statements were carefully reviewed and selected for inclusion in the book. The papers are organized in topical sections on loyalty and micropayment systems, user authentication, e-voting, auctions and lotteries, game theoretic and cryptographic tools, and mix networks and anonymous communications.