wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

22
Security in Industrial
Communication Systems
Wolfgang Granzer
Vienna University
of Technology
Albert Treytl
Austrian Academy
of Sciences
22.1 Introduction to Security in Industrial Communication........... 22-1
22.2 Planned Approach to Security: Defense in Depth.....................22-3
22.3 Security Measures to Counteract Network Attacks..................22-4
Virtual Private Networks. •. Firewalls. •. Cryptography. •. .
DoS Prevention and Detection
22.4 Security Measures to Counteract Device Attacks......................22-9
Protected Hardware and Security Token. •. Secure Software
Environments
22.5 State of the Art in Automation Systems.....................................22-12
Security in Building Automation Systems. •. Security in Industrial
Communication. •. Security in IP-Based Networks. •. Security
in Wireless Communication Systems
22.6 Outlook and Conclusion..............................................................22-15
Abbreviations............................................................................................. 22-15
References.................................................................................................. 22-16
22.1 Introduction to Security in Industrial Communication
Modern industrial communication systems go far beyond small automated islands that have been
in mind when developing the original communication protocols. Vertical integration and transmission
over the Internet are common today, but they require additional security measures to protect
the assets.
In literature, a multitude of security definitions that are more or less ambiguous exist [R49,PFL,MEN,
BIS,I15]. In the context of industrial communication, security can be defined as measures that protect
system resources against adversaries that intentionally try to gain unauthorized, malicious access. The
aim of such an access can be manifold. In the field of industrial communication, an adversary may be a
human or some piece of malicious software (e.g., Trojan horse, virus, worm) with the intention to gain
unauthorized access to control functions, i.e., functions that interact with the process under control.
Note that this definition of security is contrary to the definition of safety. While security protects the
system against intentional actions that may result in damage to the system and as a consequence may
also be harmful to people, safety measures reduce the risk of unintentional system states that do cause
harm to humans.
The actual action that an adversary performs to gain access to the control functions is generally
referred to as a security attack. A security attack is only possible if the system suffers vulnerabilities, i.e.,
flaws and weaknesses that may be exploited. The existence of vulnerabilities leads to security threats that
can be seen as the potential for violation of security. To provide measures that avoid a violation of the
system’s security, these security threats have to be determined. Note that a security attack is different to
22-1
© 2011 by Taylor and Francis Group, LLC