Industrial Automatic Control Systems and Controllers Annotation << Back Application of Blockchain Technology in Access Control Systems Yu.Yu. Gromov, P.I. Karasev, A.O. Sobolev Access control is a computer security mechanism that regulates access to system resources, is associated with determining the permitted actions of authorized users and fixing each user’s attempt to access resources in the system. Existing access control systems face many problems, such as insuffi cient effi ciency, lack of confi dentiality, man-in-the-middle attacks, and the possibility of unauthorized data modification. These problems can be solved with the help of blockchain, a technology that has attracted a lot of public attention and has great potential. This paper examines the problems of existing access control systems in automated control systems (ACS), explains how blockchain can help solve these problems, presents an analysis of access control systems for automated control systems using blockchain in terms of properties, components, architectures, and also considers potential problems of implementing a blockchain system. Keywords: blockchain, access control system, automated control system, smart contracts, decentralization. DOI: 10.25791/asu.7.2022.1376 Pp. 30-38.