Security measures for industrial fieldbus systems - state of the art and solutions for IP-based approaches

With the success of IP-based networks in the office world and the Internet as such the application of this technology also became attractive for the automation area. The design of next-generation fieldbus systems already picked up this idea. With the trend towards vertical integration in the field area and the seamless communication facilities IP-based networks offer, security gains importance. However, while security is already a topic for LANs and IP networks, the topic is only slowly gaining attention in the fieldbus segment. This paper analyses the current situation of security measures for industrial fieldbus systems. With respect to IP-based systems the focus is set to the measures that are offered for the (TCP/)IP protocol and their applicability for the special situation of industrial fieldbuses. Its shown where automation networks differ from communication relations in the Internet, and solutions for the particular security problems on the field level and the interconnection with higher levels are to be proposed.