
×
From the reviews:
„Protocols that remain zero-knowledge when many instances are executed concurrently are called concurrent zero-knowledge. This book is very well suited for the reader who wants to know the state of the art of concurrent zero-knowledge proofs. … The book could be used as a textbook on advanced topics in cryptography. It is highly recommended to the newcomer in the field who wants technical information, and to the researcher in the area who would like a survey on concurrent zero-knowledge.“ (Yongge Wang, Mathematical Reviews, Issue 2007 m)
Zero-knowledge proofs are fascinating and extremely useful constructs. Their fascinating nature is due to their seemingly contradictory de? nition; ze- knowledge proofs are convincing and yet yield nothing beyond the validity of the assertion being proved. Their applicability in the domain of cryptography is vast; they are typically used to force malicious parties to behave according to a predetermined protocol. In addition to their direct applicability in cr- tography, zero-knowledge proofs serve as a good benchmark for the study of variousproblemsregardingcryptographicprotocols(e. g.,“securecomposition of protocols”). A fundamental question regarding zero-knowledge protocols refers to the preservation of security (i. e., of the zero-knowledge feature) when many - stances are executed concurrently, and in particular under a purely as- chronous model. The practical importance of this question, in the days of extensive Internet communication, seems clear. It turned out that this qu- tion is also very interesting from a theoretical point of view. In particular, this question served as a benchmark for the study of the security of concurrent executions of protocols and led to the development of techniques for coping with the problems that arise in that setting.