Cyber security for protection and control systems - guarding the flank of the electrical power system

Is cyber security really a point of concern for our electric distribution system? If NERC states that cyber security is only “ ... required for assets on the Bulk Electric System” (those elements of the transmission or distribution system directly affecting 300 MW or more), then why are elements that are not immediately identified as “Critical Infrastructure” important? This paper addresses the need for cyber security of Intelligent Electronic Devices (IEDs) inside as well as outside the distribution substation. The paper discusses practical implementation of IEEE 1686 “Standard for Substation Intelligent Electronic Devices (IEDs) Cyber Security Capabilities” embedded inside the IED. The paper also discusses centralized Authentication, Authorization and Accounting services, secure authentication and encryption of data to provide high level of cyber security.