Secure MultiParty Computation on Blockchain: An Overview Secure multiparty computation (SMPC) is a hot topic in the field of cryptography. It focuses on finishing computation tasks without revealing usersxe2x80x99 inputs and outputs in decentralized scenarios. Although many researches have been conducted to perform SMPC protocols, it is hard to obtain fairness while most participants in SMPC are dishonest. Recently, the foundation of cryptocurrency, blockchain has attracted the attention of many scholars. Since blockchainxe2x80x99s ability to provide security and incentives, researchers start to make use of blockchain to provide fairness in SMPC protocols and increase efficiency. In this paper, we present a brief survey on how to use blockchain technology to perform SMPC protocol. We start by introducing the concept of secure computation and its security requirements. Then, we explain how we can utilize blockchain to provide fairness and present the basic model. We summarize stateoftheart blockchain based SMPC applications and conclude this paper.

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.