This book contains the proceedings of the EUROCRYPT '88 conference, a workshop on theory and applications of cryptographic techniques held at Davos, Switzerland, May 25-27, 1988. The International Association for Cryptologic Research (IACR) organizes two international conferences every year, one in Europe and one in the United States. EUROCRYPT '88 was the sixth European conference. The number of contributions and of participants at the meetinng has increased substantially, which shows the high interest in cryptography and in system security in general. The interest has also further moved towards authentication, signatures and other protocols. This is to understand in view of the urgent needs for such protocols, in particular in connection with open information systems, and in view of the exciting problems in this area. The equally fascinating classical field of secrecy, i.e. the theory, design and analysis of stream or block ciphers and of public key cryptosystems, was however also well represented and several significant results were communicated. These proceedings contain all contributions accepted for presentation.