Financial Cryptography 2000 marked the fourth time the technical, business, legal, and political communities from around the world joined together on the smallislandofAnguilla,BritishWestIndiestodiscussanddiscovernewadvances in securing electronic ?nancial transactions. The conference, sponsored by the International Financial Cryptography Association, was held on February 20– 24, 2000. The General Chair, Don Beaver, oversaw the local organization and registration. The program committee considered 68 submissions of which 21 papers were accepted. Each submitted paper was reviewed by a minimum of three referees. These proceedings contain revised versions of the 21 accepted papers. Revisions were not checked and the authors bear full responsibility for the content of their papers. This year’s program also included two invited lectures, two panel sessions, and a rump session. The invited talks were given by Kevin McCurley prese- ing “In the Search of the Killer App” and Pam Samuelson presenting “Towards a More Sensible Way of Regulating the Circumvention of Technical Protection Systems”. For the panel sessions, Barbara Fox and Brian LaMacchia mod- ated “Public-Key Infrastructure: PKIX, Signed XML, or Something Else” and Moti Yung moderated “Payment Systems: The Next Generation”. Stuart Haber organized the informal rump session of short presentations. This was the ?rst year that the conference accepted submissions electro- cally as well as by postal mail. Many thanks to George Davida, the electronic submissions chair, for maintaining the electronic submissions server. A majority of the authors preferred electronic submissions with 65 of the 68 submissions provided electronically.