Xiaohua Jia

This book systematically studies blockchain adaptability and scalability, combining theoretical analysis with practical implementation. The book provides a comprehensive exploration of blockchain adaptability and scalability solutions through six chapters. Chapter 1 introduces blockchain overviews and current scalability challenges, emphasizing the need for adaptive and scalable blockchains. Chapter 2 systematically reviews consensus protocols, from classical BFT to modern PoW, PoS, and sharding approaches, setting the theoretical foundation for subsequent chapters. Chapter 3 presents AdaptPoW, which enhances PoW blockchain adaptability and scalability through dynamic structure adjustment and efficient transaction processing. Chapter 4 presents AdaptPoS, a PoS-based system with role decoupling and filter mechanism, enabling dynamic throughput adjustment while maintaining security. Chapter 5 describes AdaptShard for sharding-based blockchains, including its transaction allocation and optimistic processing strategy for cross-shard transactions. Chapter 6 concludes with insights and future research directions.

Cloud storage is an important service of cloud computing, which offers service for data owners to host their data in the cloud. This new paradigm of data hosting and data access services introduces two major security concerns. The first is the protection of data integrity. Data owners may not fully trust the cloud server and worry that data stored in the cloud could be corrupted or even removed. The second is data access control. Data owners may worry that some dishonest servers provide data access to users that are not permitted for profit gain and thus they can no longer rely on the servers for access control. To protect the data integrity in the cloud, an efficient and secure dynamic auditing protocol is introduced, which can support dynamic auditing and batch auditing. To ensure the data security in the cloud, two efficient and secure data access control schemes are introduced in this brief: ABAC for Single-authority Systems and DAC-MACS for Multi-authority Systems. While Ciphertext-Policy Attribute-based Encryption (CP-ABE) is a promising technique for access control of encrypted data, the existing schemes cannot be directly applied to data access control for cloud storage systems because of the attribute revocation problem. To solve the attribute revocation problem, new Revocable CP-ABE methods are proposed in both ABAC and DAC-MACS.

Multiwavelength Optical Networks systematically studies the major research issues in WDM (Wavelength Division Multiplexing) optical networks, such as routing and wavelength assignment, QoS multicast routing, design of logical topologies, and placement of wavelength converters. The book consists of two parts. The first part studies the fundamental concepts and principles of WDM networks. The second part discusses advanced and research issues of WDM networks. The authors of the book have many years of working experience in the areas of computer networks and network optimization. The book discusses many difficult issues of WDM networks in a very comprehensive way. For each problem, there is a background discussion, and then the mathematical formulation, followed by the solutions.

Multiwavelength Optical Networks systematically studies the major research issues in WDM (Wavelength Division Multiplexing) optical networks, such as routing and wavelength assignment, QoS multicast routing, design of logical topologies, and placement of wavelength converters. The book consists of two parts. The first part studies the fundamental concepts and principles of WDM networks. The second part discusses advanced and research issues of WDM networks. The authors of the book have many years of working experience in the areas of computer networks and network optimization. The book discusses many difficult issues of WDM networks in a very comprehensive way. For each problem, there is a background discussion, and then the mathematical formulation, followed by the solutions.