CRYPTO is a conference devoted to all aspects of cryptological research. It is held each year at the University of California, Santa Barbara. Annual meetings on this topic also take place in Europe and are regularly published in this series under the name of EUROCRYPT. This volume presents the proceedings of the 9th CRYPTO meeting. The papers are organized into sections with the following themes: why is cryptography harder than it looks?; pseudo-randomness and sequences; cryptanalysis and implementation; signature and authentication; threshold schemes and key management; key distribution and network security; fast computation; zero-knowledge and obvious transfer, and multiparty computation.