These are the proceedings of Eurocrypt 2004 the 23rd Annual Eurocrypt C- ference. The
conference was organized by members of the IBM Zurich Research Laboratory in cooperation with
IACR the International Association for Cr- tologic Research.
Theconferencereceivedarecordnumberof206submissions outofwhichthe program committee selected 36
for presentation at the conference (three papers were withdrawn by the authors shortly after
submission). These proceedings contain revised versions of the accepted papers. These revisions
have not been checked for correctness and the authors bear full responsibility for the
contents of their papers. The conference program also featured two invited talks. The ?rst one
was the 2004 IACR Distinguished Lecture given by Whit?eld Di?e. The second invited talk was by
Ivan Damg? ard who presented Paradigms for Multiparty Computation. The traditional rump session
with short informal talks on recent results was chaired by Arjen Lenstra. The reviewing process
was a challenging task and many good submissions had to be rejected. Each paper was reviewed
independently by at least three members of the program committee and papers co-authored by a
member of the program committee were reviewed by at least six (other) members. The individual
reviewing phase was followed by profound and sometimes lively d- cussions about the papers
which contributed a lot to the quality of the ?nal selection. Extensive comments were sent to
the authors in most cases.
