A series of workshops devoted to modern cryptography began in Santa Barbara,California in 1981 and was followed in 1982 by a European counterpart in Burg Feuerstein, Germany. The series has been maintained with summer meetings in Santa Barbara and spring meetings somewhere in Europe. At the 1983 meeting in Santa Barbara the International Association for Cryptologic Research was launched and it now sponsors all the meetings of the series. This volume presents the proceedings of Eurocrypt '92, held in Hungary. The papers are organized into the following parts: Secret sharing, Hash functions, Block ciphers, Stream ciphers, Public key I, Factoring, Trapdoor primes and moduli (panel report), Public key II, Pseudo-random permutation generators, Complexity theory and cryptography I, Zero-knowledge, Digital knowledge and electronic cash, Complexity theory andcryptography II, Applications, and selected papers from the rump session. Following the tradition of the series, the authors produced full papers after the meeting, in some cases with revisions.

Crypto'92 took place on August 16-20, 1992. It was the twelfth in the series of annual cryptology conferences held on the beautiful campus of the University of California, Santa Barbara. Once again, it was sponsored by the International Association for Cryptologic Research, in cooperation with the IEEE Computer Society Technical Committee on Security and Privacy. The conference ran smoothly, due to the diligent efforts of the g- eral chair, Spyros Magliveras of the University of Nebraska. One of the measures of the success of this series of conferences is represented by the ever increasing number of papers submitted. This year, there were 135 submissions to the c- ference, which represents a new record. Following the practice of recent program comm- tees, the papers received anonymous review. The program committee accepted 38 papers for presentation. In addition, there were two invited presentations, one by Miles Smid on the Digital Signature Standard, and one by Mike Fellows on presenting the concepts of cryptology to elementary-age students. These proceedings contains these 40 papers plus 3 papers that were presented at the Rump Session. I would like to thank all of the authors of the submitted papers and all of the speakers who presented papers. I would like to express my sincere appreciation to the work of the program committee: Ivan Damgard (Aarhus University, Denmark), Odd Goldreich (Technion, Israel), Burt Kaliski (RSA Data Security, USA), Joe Kilian (NEC, USA).

Eurocrypt is a series of open workshops on the theory and application of cryptographic techniques. These meetings have taken place in Europe every year since 1982 and are sponsored by the International Association for Cryptologic Research. Eurocrypt '93 was held in the village of Lofthus in Norway in May 1993. The call for papers resulted in 117 submissions with authors representing 27 different countries. The 36 accepted papers were selected by the program committee after a blind refereeing process. The papers are grouped into parts on authentication, public key, block ciphers, secret sharing, stream ciphers, digital signatures, protocols, hash functions, payment systems, and cryptanalysis. The volume includes 6 further rump session papers.