This book constitutes the refereed proceedings of the 11th International Workshop on Fast Software Encryption, FSE 2004, held in Delhi, India in February 2004.
The 28 revised full papers presented together with 2 invited papers were carefully reviewed and selected from 75 submissions. The papers are organized in topical sections on algebraic attacks, stream cipher cryptanalysis, Boolean functions, stream cipher design, design and analysis of block ciphers, cryptographic primitives-theory, modes of operation, and analysis of MACs and hash functions.