This book contains the proceedings of the EUROCRYPT '87 conference, a workshop on theory and applications of cryptographic techniques held at Amsterdam, April 1987. 26 papers were selected from over twice that number submitted to the program committee. The authors come from Europe, North America, and Japan and represent some of the leading research groups working in the fields of cryptography and data security. The subjects covered include sequences and linear complexity; hardware considerations, including random sources, physical security, and cryptographic algorithm implementation; topics in public key cryptography; authentication and secure transactions; hash functions and signatures; and the theory and application of symmetric ciphers.