With the recent debacle of cryptocurrency exchange FTX and the crypto trading company Alameda Research, the importance of comprehending the security and regulations of Web3, cryptocurrency, and blockchain projects has been magnified. To avoid similar economic and security failures in future Web3 projects, the book provides an essential guide that offers a comprehensive and systematic approach to addressing security concerns. Written by experts in tech and finance, it provides an objective, professional, and in-depth analysis of security and privacy issues associated with Web3 and blockchain projects. This book highlights the security related to foundational Web3 building blocks such as blockchain, crypto wallets, smart contracts, and token economics, and describes recommended security processes and procedures for Web3 application development such as DevSecOps, data analytics, and data authenticity via the oracle. Moreover, the book discusses the legal and regulatory aspects of Web3 and the reasons behind the failures of well-known Web3 projects. It also contains detailed case studies of web3 projects, analyses of the reasons for their failures, and some pending legal cases. This book is an excellent resource for a diverse range of readers, with particular appeal to web3 developers, architects, project owners, and cybersecurity professionals seeking to deepen their knowledge of Web3 security.