This book focuses on the different representations and cryptographic properties of Booleans functions, presents constructions of Boolean functions with some good cryptographic properties. More specifically, Walsh spectrum description of the traditional cryptographic properties of Boolean functions, including linear structure, propagation criterion, nonlinearity, and correlation immunity are presented. Constructions of symmetric Boolean functions and of Boolean permutations with good cryptographic properties are specifically studied. This book is not meant to be comprehensive, but with its own focus on some original research of the authors in the past. To be self content, some basic concepts and properties are introduced. This book can serve as a reference for cryptographic algorithm designers, particularly the designers of stream ciphers and of block ciphers, and for academics with interest in the cryptographic properties of Boolean functions.

This book constitutes the thoroughly refereed post-conference proceedings of the 7th International Conference on Information Security and Cryptology, Inscrypt 2011, held in Beijing, China, in November/December 2011. The 24 revised full papers presented together with 2 invited talks were carefully reviewed and selected from 80 submissions. The papers present research advances in the areas of information security, cryptology, and their applications.

This book focuses on the different representations and cryptographic properties of Booleans functions, presents constructions of Boolean functions with some good cryptographic properties. More specifically, Walsh spectrum description of the traditional cryptographic properties of Boolean functions, including linear structure, propagation criterion, nonlinearity, and correlation immunity are presented. Constructions of symmetric Boolean functions and of Boolean permutations with good cryptographic properties are specifically studied. This book is not meant to be comprehensive, but with its own focus on some original research of the authors in the past. To be self content, some basic concepts and properties are introduced. This book can serve as a reference for cryptographic algorithm designers, particularly the designers of stream ciphers and of block ciphers, and for academics with interest in the cryptographic properties of Boolean functions.

The Third SKLOIS Conference on Information Security and Cryptology (- scrypt2007)wasorganizedbytheStateKeyLaboratoryofInformationSecurity of the Chinese Academy of Sciences in cooperation with Qinhai University for Nationalities. This international conference was held in Xining, Qinhai Province of China, and was sponsored by the Institute of Software, the Chinese Academy of Sciences, the Graduate University of the Chinese Academy of Sciences and the National Natural Science Foundations of China. By now, Inscrypt (the International SKLOIS Conference on Information - curity and Cryptology) has become a tradition, and it is, in fact, a leading event in this area, which takes place annually in China. We are pleased with the continuous support by authors, committee members, reviewers, sponsors and organizers. Indeed, the research areas covered by Inscrypt are important, since modern computing (including communication infrastructures and applications) requires increased security, trust, safety and reliability. This need has motivated the research community worldwide to produce important fundamental, exp- imental and applied work in the wide areas of cryptography and information securityresearchin recent years.Accordingly, the programof Inscrypt 2007c- ered numerous ?elds of research within these general areas