Key Words: IEC-62541 (OPC-UA) standard; Industry 4.0 reference architecture; cyber-attacks; security recommendations; OPC-UA applications.
Abstract. The IEC-62541 (OPC-UA) standard is an important part of the Industry 4.0 reference architecture and is recommended as the only possible communication standard. A particularly important issue that is being addressed is the issue of security. The paper analyzes the vulnerability of cyber-attacks and the main threats that threaten the security of OPC-UA-based applications and defines established and sustainable recommendations for increasing the security of these applications.