This handbook is a selection of foundational aspects, security analysis, platforms, and applications of blockchains that consists of four parts. The first part introduces the basic building blocks such as distributed computing and cryptography. Consensus algorithms that form the basic backbone of blockchain protocols are presented. Various cryptographic tools like hash functions, digital signatures and commitment schemes are also introduced. Advanced cryptographic techniques such as zero knowledge protocols, secret sharing, verifiable random functions that are used for privacy-preserving and secure design are discussed.  The second part of this handbook consists of popular blockchain designs and platforms. Architecture of Bitcoin, Ethereum, Monero, Tendermint and Algorand have been presented. Various important issues like scalability and security are discussed in the third part. Security design challenges, security vulnerabilities and their analysis are discussed. The final part of this handbook discusses various applications of blockchains. These include supply-chain, identity and credential management, Internet of Things (IoT), data-sharing, e-voting, e-governance, e-health, smart cities, and Industry 4.0. Research challenges and directions of future work are included in this handbook. This comprehensive reference targets students and researchers, who are starting to explore blockchain. Professionals working in blockchain security and applications will find this handbook to be a valuable reference.

This book constitutes the refereed proceedings of the 26th Australasian Conference on Information Security and Privacy, ACISP 2021, held in Perth, WA, Australia, in November 2021.The 35 full papers presented were carefully revised and selected from 157 submissions. The papers present and discuss all aspects of information security and privacy as well as machine learning for privacy and much more.

This book constitutes the refereed proceedings of the 20th International Conference on Cryptology in India, INDOCRYPT 2019, held in Hyderabad, India, in December 2019. The 28 revised full papers presented in this book were carefully reviewed and selected from 110 submissions (of which 20 were either rejected without being reviewed or withdrawn before the deadline). The focus of the conference includes works on signatures and filter permutators; symmetric key ciphers and hash functions; blockchain, secure computation and blind coupon mechanism; oblivious transfer, obfuscation and privacy amplification; Boolean functions, elliptic curves and lattices; algorithms, attacks and distribution; and efficiency, side-channel resistance and PUFs.