This book constitutes the thoroughly refereed post-proceedings of the 9th International Conference on Financial Cryptography and Data Security, FC 2005, held in Roseau, The Commonwealth Of Dominica, in February/March 2005.

The 24 revised full papers presented together with the abstracts of one invited talk and 2 panel statements were carefully reviewed and selected from 90 submissions. The papers are organized in topical sections on threat and attacks, digital signing methods, privacy, hardware oriented mechanisms, supporting financial transactions, systems, applications, and experiences, message authentication, exchanges and contracts, auctions and voting, and user authentication.