Blockchain 3.0 for Sustainable Development

Deepak Khazanchi, Ajay Kumar Vyas, Kamal Kant Hiran, Sanjeevikumar Padmanaban, Deepak Khazanchi, Ajay Kumar Vyas, Kamal Kant Hiran, Sanjeevikumar Padmanaban

• Éditeur: De Gruyter
• Année: 2021
• ISBN:
  9783110702576
• Édition: 1
• Sujet: Informatique
• Sous-sujet: Technologies de l'information

This book will focus on the use of Blockchain 3.0 for sustainable development. This tool is invaluable for achieving transparency and trust, but possibilities to benefit society more broadly are emerging that will bring a bright future for sustainable development, too. The adoption of blockchain in agriculture, healthcare, infrastructure, education, environment, energy, communication will provide revolutionary changes in the digital era.

Chapter 1 Blockchain technology: architecture, consensus protocol and applications

Himani Mittal

Goswami Ganesh Dutta Sanatan Dharma College, Chandigarh, India

Abstract

Blockchain technology is a database of transactions. It is immutable, distributed, transparent and secure. Blockchain technology is an upcoming technology that has tremendous scope. This chapter discusses the components of a blockchain and its applications. The components of a blockchain include block, linked list, chain, genesis block and consensus protocol. A block is a single transaction. Blockchain is a collection of blocks linked by hash cryptography. Each user on the blockchain has a dedicated chain. The consensus protocol defines the mechanism using which transactions are added to the blockchain. The design of consensus protocol emphasizes on suitability to fight against network attacks and fast database update. Some consensus protocols included in this chapter are proof of work, proof of stake and proof of elapsed time. The several applications of blockchain as namely, internet of things, cloud computing, healthcare, medicine, storage and education. Smart city development and financial applications are other domains of use.

Keywords: blockchain, distributed ledger, consensus protocol, decentralized database, applications of blockchain,

1.1 Introduction

Blockchain technology became popular in the research fraternity through the introduction of Cryptocurrency. In 2008, the author named Satoshi Nakamoto published a paper entitled “Bitcoin: A Peer-to-Peer Electronic Cash System.” This chapter described a peer-to-peer (P2P) electronic cash system where payments are made directly from one party to another without involving any bank or third party (regulator). These types of cash systems are known as cryptocurrency. Cryptocurrency makes use of cryptography to secure transactions and hence the name. This cryptocurrency is based on blockchain technology.

A blockchain is a digital record of transactions or a database of transactions. The name comes from its structure, in which individual records, called blocks, are linked together in a single list, called a chain. The blockchain is a distributed ledger that ensures immutability, transparency and security.

• Immutability means data once saved cannot change.
• Distributed means there is no single owner that controls the blockchain database. It is spread across a network of participants.
• Transparency means that whatever changes happen in the database are visible to all the participants. This might raise a security concern but the blockchain is transparent, at the same time secure, and hides the identity of participants from each other.

These properties make blockchain an open area of research with plenty of active implementations. There lies an unlimited powerful application domain based on blockchain technology [1, 2].

The organization of the chapter is as follows: Section 1.2 includes the architecture of blockchain. The consensus protocols are discussed in Section 1.3. The current applications of blockchain are discussed in Section 1.4, and Section 1.5 concludes the chapter.

1.2 Blockchain architecture

The blockchain includes the following components: block, blockchain, hash cryptography, immutable ledger, distributed P2P network and consensus protocol. These components are shown in Figure 1.1. The details are as follows.

1.2.1 Block

The most basic unit of a blockchain database is the block. It contains the transactions to store. Figure 1.1 shows the structure of block. It consists of block number, nonce, data, previous hash and hash. The block number is a unique number assigned to each block generated by the user who creates the block. The nonce is a special value mined by the miner algorithms employed by the creator of the block. This value calculation is also known as puzzle solving. Previous hash is the encryption of the previous block. The hash is calculated using SHA-256 algorithm on the combination of the nonce, previous hash and data.

Figure 1.1: Structure of a block.

To ensure immutability and security of the data, nonce, previous hash and hash, are used. The use of this hash value is that the hash of the previous block is stored in the next block and used in the calculation of new hash. This ensures that if anyone tries to change an intermediary block in the blockchain, then all the hashes of all the blocks will have to be recalculated, which is impossible. This ensures that data once added cannot be changed in the blockchain. This property makes blockchain suitable for applications that are transactional in nature and where the previous data should never be modified. Nonce is utilized to ensure that the hash value generated for a block has a particular format like starting with 3 zeroes or 10 zeroes.

After a block is added to the blockchain network, it is immutable. The size of the block limits the amount of data it can hold. The blockchain network decides the block size at the time of the creation of the network.

Generally, when a new user is added to the blockchain network, a new chain is started for the user. This chain consists of a genesis or starting block. Then, the subsequent blocks containing user data are stored in a new block and appended to this genesis block, in the form of a linked list. This collection of the genesis block and all subsequent blocks is the blockchain. Collection of these blockchains is the complete database.

1.2.2 Blockchain

After the creation of the genesis block of the user, all the transactions of that user are linked to it as shown in Figure 1.2. The previous hash in the genesis block is zero as there is no previous block. Genesis block contains data about the user like name and the hash value assigned to that user. Then the nonce and a new hash are calculated. Then as the transactions happen, the new blocks will be appended to this starting block. However, adding a block to this blockchain is not a simple job. It needs to go to the P2P network through consensus protocol.

Figure 1.2: Blockchain in network.

1.2.3 Hash cryptography

The SHA...

Table des matières

• Title Page
• Copyright
• Contents
• Editors’ brief bio
• Chapter 1 Blockchain technology: architecture, consensus protocol and applications
• Chapter 2 Blockchain: implications for accounting and audit practice
• Chapter 3 Paradigms to make smart city using blockchain
• Chapter 4 Measuring barriers in adoption of blockchain in supply chain management system
• Chapter 5 Emerging opportunities for the application of blockchain for energy efficiency
• Chapter 6 Measuring professionals’ perception on blockchain-based futuristic accounting
• Chapter 7 Blockchain 3.0 for sustainable healthcare
• Chapter 8 Enhanced fingerprint authentication using blockchain
• Chapter 9 Novel feature extraction and classification architecture for emotion recognition using EEG
• Chapter 10 Future of fashion industry: sustainable fashion using blockchain
• Index