This volume contains the proceedings of the 13th International Conference on Financial Cryptography and Data Security, held at the Accra Beach Hotel and Resort, Barbados, February 23-26, 2009. Financial Cryptography and Data Security (FC) is a well-established int- national forum for research, advanced development, education, exploration and debate regarding information assurance in the context of ?nance and commerce. The conference covers all aspects of securing transactions and systems. The goal of FC is to bring security and cryptography researchers and pr- titioners together with economists, bankers, and policy makers. This year, we assembled a vibrant program featuring 21 peer-reviewed research paper pres- tations, two panels (on the economics of information security and on authen- cation), and a keynote address by David Dagon. Despite a proliferation of security and cryptography venues, FC continues to receive a large number of high-quality submissions. This year, we received 91 submissions(75full-lengthpapers,15shortpapersand1panel).Eachsubmission was reviewed by at least three reviewers. Following a rigorous selection, ranking and discussion process, the Program Committee accepted 20 full-length papers, 1 short paper and 1 panel. The overall acceptance rate was 24%.