Security considerations for the WirelessHART protocol

WirelessHART is a secure and reliable communication standard for industrial process automation. The WirelessHART specifications are well organized in all aspects except security: there are no separate specifications of security requirements or features. Rather, security mechanisms are described throughout the documentation. This hinders implementation of the standard and development of applications since it requires profound knowledge of all the core specifications on the part of the developer. In this paper we provide a comprehensive overview of WirelessHART security: we analyze the provided security mechanisms against well known threats in the wireless medium, and propose recommendations to mitigate shortcomings. Furthermore, we elucidate the specifications of the security manager, its placement in the network, and interaction with the network manager.