Book Image

Mastering Blockchain - Third Edition

By : Imran Bashir
Book Image

Mastering Blockchain - Third Edition

By: Imran Bashir

Overview of this book

Blockchain is the backbone of cryptocurrencies, with applications in finance, government, media, and other industries. With a legacy of providing technologists with executable insights, this new edition of Mastering Blockchain is thoroughly revised and updated to the latest blockchain research with four new chapters on consensus algorithms, Serenity (the update that will introduce Ethereum 2.0), tokenization, and enterprise blockchains. This book covers the basics, including blockchain’s technical underpinnings, cryptography and consensus protocols. It also provides you with expert knowledge on decentralization, decentralized application development on Ethereum, Bitcoin, alternative coins, smart contracts, alternative blockchains, and Hyperledger. Further, you will explore blockchain solutions beyond cryptocurrencies such as the Internet of Things with blockchain, enterprise blockchains, tokenization using blockchain, and consider the future scope of this fascinating and disruptive technology. By the end of this book, you will have gained a thorough comprehension of the various facets of blockchain and understand their potential in diverse real-world scenarios.
Table of Contents (24 chapters)
23
Index

Oracles

Oracles are an essential component of the smart contract and blockchain ecosystem. The limitation with smart contracts is that they cannot access external data because blockchains are closed systems without any direct access to the real world. This external data might be required to control the execution of some business logic in the smart contract; for example, the stock price of a security product that is required by the contract to release dividend payments. In such situations, oracles can be used to provide external data to smart contracts. An oracle can be defined as an interface that delivers data from an external source to smart contracts. Oracles are trusted entities that use a secure channel to transfer off-chain data to a smart contract.

The following diagram shows a generic model of an oracle and smart contract ecosystem:

Figure 10.3: A generic model of an oracle and smart contract ecosystem

Depending on the industry and use case requirements, oracles...