Security, Performance, and Applications of Smart Contracts: A Systematic Survey

Blockchain is the promising technology of recent years, which has attracted remarkable attention in both academic studies and practical industrial applications. The smart contract is a programmable transaction that can perform a sophisticated task, execute automatically, and store on the blockchain. The smart contract is the key component of the blockchain, which has made blockchain a technology beyond the scope of the cryptocurrencies and applicable for a variety of applications such as healthcare, IoT, supply chain, digital identity, business process management, and more. Although in recent years the progress toward improving blockchain technology with the focus on the smart contract has been impressive, there is a lack of reviewing the smart contract topic. This paper systematically reviews the key concepts and proposes the direction of recent studies and developments regarding the smart contract. The research studies are presented in three main categories: 1) security methods and tools; 2) performance improvement approaches; and 3) decentralized applications based on smart contracts.