A DNP3-based SCADA Architecture Supporting Electronic Signatures

Security of industrial control systems is a well-known issue, and it has become stringent given the vulnerabilities of the widely available, modern communication technologies, and new paradigms such as Internet of Things. Another related issue concerns the redundancy of an interconnected industrial system, while distributing the data processing capabilities in separated physical or geographical components of a SCADA-based system. Our paper deals with some of the security issues, within the Distributed Network Protocol (DNP3). In the context of Intelligent Electronic Devices acting as Remote Terminal Units (RTU), we have studied the ways in which data integrity and data-origin authentication is handled in SCADA architectures, and found that the benefits offered by electronic signatures can be incorporated within such architectures, while preserving the performance criteria. Modern RTUs are capable to handle networks of sensors, to fusion their acquired data and deliver this data through a secure communication line to a master terminal unit. We have proposed a new architectural solution by modifying the Link Protocol Data Unit of DNP3, such that support for data integrity and data-origin authentication is ensured by means of electronic signature.