Book excerpt: This book constitutes the refereed proceedings of the 24th Annual International Cryptology Conference, CRYPTO 2004, held in Santa Barbara, California, USA in August 2004. The 33 revised full papers presented together with one invited paper were carefully reviewed and selected from 211 submissions. The papers are organized in topical sections in linear cryptanalysis, group signatures, foundations, efficient representations, public key cryptanalysis, zero-knowledge, hash collision, secure computation, stream cipher cryptanalysis, public key encryption, bounded storage model, key management, and computationally unbounded adversaries.