Blockchain technology is a powerful, cost-effective method for network security. Essentially, it is a decentralized ledger for storing all committed transactions in trustless environments by integrating several core technologies such as cryptographic hash, digital signature and distributed consensus mechanisms. Over the past few years, blockchain technology has been used in a variety of network interaction systems such as smart contracts, public services, Internet of Things (IoT), social networks, reputation systems and security and financial services. With its widespread adoption, there has been increased focus on utilizing blockchain technologies to address network security concerns and vulnerabilities as well as understanding real-world security implications. The book begins with an introduction to blockchains, covering key principles and applications. Further chapters cover blockchain system architecture, applications and research issues; blockchain consensuses and incentives; blockchain applications, projects and implementations; blockchain for internet of things; blockchain in 5G and 6G networks; edgechain to provide security in organization based multi agent systems; blockchain driven privacy-preserving machine learning; performance evaluation of differential privacy mechanisms in blockchain based smart metering; scaling-out blockchains with sharding; blockchain for GIS; and finally blockchain applications in remote sensing big data management and production.
Inspec keywords: smart meters; learning (artificial intelligence); multi-agent systems; Big Data; 6G mobile communication; computer network security; geographic information systems; distributed databases; remote sensing; Internet of Things; cryptography; data privacy; 5G mobile communication
Other keywords: network security; privacy-preserving machine learning; remote sensing big data management; 6G networks; sharding; edgechain; 5G networks; smart metering; Internet of Things; multiagent systems; GIS; blockchains
Subjects: General electrical engineering topics; Knowledge engineering techniques; Mobile radio systems; General and management topics; Distributed databases; Computer communications; Security aspects of hardware; Computing security management; Geophysics computing; Data security; Geophysical techniques and equipment; Computer networks and techniques; Geography and cartography computing; Cryptography
A blockchain is a distributed database or ledger that maintains an ever-growing list of data records in opposition to tampering and revision. It provides immutable data storage over a distributed network and supports a large number of encrypted and coded interactions, which improves the reliability of the entire network interaction system and reduces the need for trust. Even if some nodes in the blockchain are hacked and fail, the system can run as usual. (In such a scenario, users are enabled to form a distributed peer -to peer (P2P) network in which they could interact with each other in an efficient manner without a trusted intermediary). In addition to being famous for decentralization, blockchain has shown other significant characteristics during its development, such as reliability, anonymity, transparency, auditability and programming. According to the different degree of openness and coverage, the current blockchain can be classified into three categories: public blockchain, consortium blockchain and private blockchain. In this process, the evolution of blockchain has gone through three processes: blockchain 1.0, 2.0 and 3.0. Blockchain 1.0, known as digital currency stage, is strongly related with the decentralization and payment of cryptocurrencies. Blockchain 2.0, known as digital finance stage, introduces economic, financial and market applications by programming far from simple currency transactions. Among them, the most significant features of blockchain 2.0 are the introduction and application of smart contracts. Blockchain 3.0, known as digital society stage, provides decentralized solutions for a variety of industries beyond just financial scene.
Blockchain is a technological revolution from the centralized system to securely distributed system. It covers multiple scientific domains, including cryptography, distributed storage, consensus mechanisms, smart contracts and other technologies, establishing a new type of trust and incentive system, which greatly enhances transparency and reduces credit risk. In this chapter, our aim is to demonstrate a system architecture of blockchain system to provide a whole view of the blockchain system. Then we presented the function of each layer in the system architecture with details of how each layer contributes to the key features of the blockchain system. Furthermore, we provide some key blockchain applications to show its potential in improving the efficiency and security of social service provisioning. Finally, we discussed some key challenges that blockchain meets due to its inherent design. The solutions to address these problems require the active exploration and cooperation of all parties to jointly build a new digital society that is convenient and reliable.
As the core of a blockchain system, the consensus mechanism not only helps to maintain the consistency of nodes' data but also gets involved in issuance of tokens and prevention of attacks. Since the first blockchain system was born in 2009, it has been continuously improved with the development of the blockchain technology and evolved into multiple new branches. Starting with the basic introduction of the consensus and the classic Byzantine Generals Problem in distributed computing area, this chapter proposes a thorough classification of current consensus protocols in blockchain system, enumerates the characteristics of mainstream protocols (proof-of-work (PoW), proof-of-stake (PoS), delegated PoS (DPoS), practical Byzantine fault tolerance (PBFT), etc.) and analyzes the strengths and weaknesses of them. Then we compare the performances of them from the number of nodes to the degree of scalability and other aspects. In the end, we introduce the incentive mechanism in the design of a consensus and summarize the future directions of developing more practical consensus schemes.
In this chapter, we first present potential blockchain applications in the world and then summarize the ongoing blockchain projects and its implementations, along with comprehensive compares among them.
Internet of Things (IoT) technology is digitizing the physical world by connecting enormous and heterogeneous devices and unleashing great economic benefit. However, data privacy, security and trust issues in current solutions are seriously limiting the adoption of IoT applications. Blockchain, a decentralized and tamperresistant ledger, maintains consistent and immutable blocks of data at different servers and has the potential to tackle the security concerns in IoT applications. Inherent features in IoT, such as the massive IoT devices, heterogeneous IoT networks, limited battery, low computing power and communication bandwidth, make it hard to directly adopt blockchain technology in IoT application. This chapter presents a comprehensive survey on existing blockchain and IoT technologies and emphasizes on the challenges and limitation. Current studies, projects and designs on Blockchain-IoT systems are introduced and compared to illustrate the feasibility of the integration of blockchain and IoT. Blockchain technologies that can potentially address the critical challenges in IoT applications and suit the features of the same are identified with potential adaptations and enhancements elaborated on blockchain data structures, key blockchain technologies and consensus protocols. Future research directions of blockchain are collated for effective adoption in IoT applications.
Although the blockchain was introduced in 2008 by Nakamoto, it has developed into a hot topic because of its decentralized characteristics. The evolution of the wireless network is moving from 4G to 5G and 6G networks. So the research on the combination of blockchain and 5G and 6G networks should be carried out as soon as possible. In this chapter, we have presented a detailed survey of the blockchainenabled technologies, applications and services in 5G and 6G networks. Moreover, the challenges and solutions, such as security -related, privacy -related and other related, of deploying blockchain in 5G and 6G networks, are also proposed. We hope that this discussion will stimulate interest and further research on implementing blockchain in future 5G and 6G networks.
Organization-based multi-agent systems (MASs) are open distributed systems, to which other distributed intelligent systems can be connected. The scalability of virtual organizations (VOs) is an advantage in the development of smart distributed systems, but at the same time it can create security issues as the newly incorporated systems may be malicious. To ensure the security of the system, this work proposes the use of a main blockchain with additional blockchains created by new VOs, which support the main system. Another advantage of agent organizations is that they can be created according to the needs of the system and their function may change whenever required. This chapter introduces the concept of EdgeChain, and a case study is conducted with bank transactions to evaluate the proposal. On certain days of the month, banks have an increase in transactions due to the payment of bills, payroll income, etc. The proposed model is based on virtual agent organizations and will be used to create EdgeChains that optimize on-demand bank transactions. EdgeChains will be created with certain specifications as required (e.g. more processing capacity). In this work, we present a new method based on VOs of agents and blockchain technology, designed to improve the processes according to demand.
With the integration of blockchain with current leading privacy-preserving machine learning mechanism, the performances of FL and GAN-DP can be further improved, especially the robustness against poisoning attacks. In addition, the deployment of blockchain as the underlying architecture enables decentralization while providing incentive mechanisms. Furthermore, the efficiency can be guaranteed, and the storage resources can be saved with an off-chain structure. Future directions in this field may include the optimization using game theory and reversible blockchain using chameleon hash.
In this chapter, the author first work over the integration of differential privacy and blockchain in real-time smart metering scenario. Afterwards, we carried out performance evaluation of four variants of differential privacy in the proposed blockchain-based smart metering scenario. The performance evaluation section of this chapter demonstrates that each privacy -preserving mechanism adds differently depending upon the selected privacy parameters and the input data. However, in the case of high peak values the Geometric mechanism surpasses other noise addition variants, although, in case of low peak values in metre reading, the Laplace mechanism performs better at ε = 0.01. As a part of future work, we are working over the integration of differential privacy and blockchain in other cyber-physical systems scenarios.
The blockchain technology, featured with its decentralized tamper -resistance based on a peer -to -peer (P2P) network, has been widely applied in financial applications and even further been extended to industrial applications. However, the weak scalability of traditional blockchain technology severely affects the wide adoption due to the well-known trilemma of decentralization-security-scalability in block chains. In regards to this issue, a number of solutions have been proposed, targeting to boost the scalability while preserving the decentralization and security. They range from modifying the on -chain data structure and consensus algorithms to adding the off -chain technologies. Therein, one of the most practical methods to achieve horizontal scalability along with the increasing network size is sharding, by partitioning network into multiple shards so that the overhead of duplicating communication, storage, and computation in each full node can be avoided.
Distributed technology is an important direction in the field of geographic information system (GIS). However, distributed GIS is facing a number of challenges such as decentralization, geospatial data sharing, and privacy and security vulnerabilities. Blockchain technology brings the opportunities in addressing the challenges of GIS. In this chapter, we investigate the integration of blockchain technology with GIS and discuss the opportunities of blockchain GIS. Moreover, our novel architecture of blockchain GIS is proposed, while the potential applications of blockchain GIS are described in detail. Finally, we outline the open research directions in the promising area.
The rise of blockchain technology provides new ideas for remote sensing big data management and production and overcomes challenges to data tampering detection, process recording, process accuracy evaluation, and private data protection. The introduction of blockchain technology into remote sensing big data management and production will surely give full play to the value of remote sensing data sources and provide increasingly credible decision -making knowledge for global change research. Therefore, we carried out a prospective study on blockchain-based strategies for remote sensing big data management and product generation. Specifically, we proposed remote sensing big data management rules for metadata entering chain, image files remaining in the original storage, and watermarking to maintain consistency on -chain and off -chain. In addition, we established the UMNI to solve the problem of heterogeneous metadata in multisource data integration and constructed a data block structure containing metadata identification, image encryption paths, and other information. We proposed technical solutions for multisource remote sensing data integration, chain entry, and sharing and established the specific steps and technical details of the blockchain-based product production. Finally, we constructed a logical blockchain-based system serving remote sensing big data management and product generation under a multi -satellite data center scenario.
