A Survey on Security and Privacy Issues of Blockchain Technology

Blockchain technology offers great benefits to the development of information technology. However, in order to use blockchain effectively, it is necessary to consider security and privacy aspects. This paper presents a survey of different security and privacy aspects of blockchain. In particular, we present the common types of security attacks on blockchain and security enhancement solutions. We also focus on the existing solutions to protect privacy for blockchain, and on the directions for future research using group signature and zeroknowledge schemes. Group signature scheme can be used to validate transactions in a blockchain network, and zero-knowledge to guarantee that transactions are valid despite the fact that the detailed information of transactions remains obscure. The combination of group signature and zeroknowledge could be feasible solutions for improving security and privacy for blockchain. This solution could also be deployed for IoT networks.