Application of Distributed Ledger Technology to Protect Smart Cities: Challenges and Solutions

The concept of a Smart City involves transparent information exchange between decentralized cyber environments using distributed ledger technology (DLT). Unlike a centralized database, the distributed ledger does not require a central administrator and therefore does not have a single (central) point of failure. However, this technology has the following problems: (1) majority attacks on DLT systems; (2) assessment of the current level of DLT system security; (3) constant growth in blockchain file size. As a result of the analysis of studies devoted to solving these issues, it was found that today the known solutions have a number of limitations that do not allow them to completely solve these problems. The paper reviews a new approach aimed at consistently solving these challenges. To protect DLT systems in Smart Cities against majority attacks, the method based on dynamic neutralization of the destructive effects of the intruder is proposed. To assess the security level of DLT systems, a method based on calculating the performance of DLT nodes is discussed. To reduce the volume of the block graph, there is presented a new structure of a DLT system. An experimental study has shown the effectiveness of the proposed approach.