Using the security triad to assess blockchain technology in public sector applications Abstract   This conceptual paper explores the impact of blockchain technology on public sector processes through the lens of information security. It includes an overview of the evolution of egovernment, a synopsis of existing applications of blockchain technology, and innovative blockchain developments. We utilize the ConfidentialityIntegrityAccessibility (CIA) triad to guide our discussion of the security, governance, and regulatory implications of this technology. Leveraging the CIA triad model, we provide context for public managers who may consider blockchain technologies, and we highlight certain advantages arising from the xe2x80x9cnonreputabilityxe2x80x9d of distributed ledgers.  In particular, we highlight the advantages of blockchain technologies with regards to nonreputability to help public managers understand how to best leverage blockchain technology to transform operations.

Security and Privacy on Blockchain Blockchain offers an innovative approach to storing information, executing transactions, performing functions, and establishing trust in an open environment. Many consider blockchain as a technology breakthrough for cryptography and cybersecurity, with use cases ranging from globally deployed cryptocurrency systems like Bitcoin, to smart contracts, smart grids over the Internet of Things, and so forth. Although blockchain has received growing interests in both academia and industry in the recent years, the security and privacy of blockchains continue to be at the center of the debate when deploying blockchain in different applications. This paper presents a comprehensive overview of the security and privacy of blockchain. To facilitate the discussion, we first introduce the notion of blockchains and its utility in the context of Bitcoin like online transactions. Then we describe the basic security properties that are supported as the essential requirements and building blocks for Bitcoin like cryptocurrency systems, followed by presenting the additional security and privacy properties that are desired in many blockchain applications. Finally, we review the security and privacy techniques for achieving these security properties in blockchainbased systems, including representative consensus algorithms, hash chained storage, mixing protocols, anonymous signatures, noninteractive zeroknowledge proof, and so forth. We conjecture that this survey can help readers to gain an indepth understanding of the security and privacy of blockchain with respect to concept, attributes, techniques and systems.