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

28-8 Industrial Communication Systems
The security issues of wireless mesh networks are similar to the security issues of other communications
networks: availability, authenticity, integrity, and confidentiality. Attackers can affect the availability
of the network by employing signal jamming. A defense against signal jamming is frequency
hopping and spread spectrum, which widens the jamming range and changes frequencies periodically.
Authenticity refers to nodes in a WMN ensuring the identity of their peer nodes. An authentication
mechanism can be implemented on the basis of public key cryptography. Integrity is ensuring that the
contents of a communication between sender and receiver is preserved intact. Integrity can be achieved
through cryptography and the use of digital signatures. Confidentiality is ensuring that data is protected
from breaches by unauthorized persons. Confidentiality can be achieved through the authentication
mechanism previously discussed as well as encrypting the communications session.
A WMN has multiple nodes and channels in an open wireless environment that are open to attack.
Eavesdropping on wireless channels and injecting fake messages into the channel is a potential threat.
The self-healing adaptive change of network topology may make it easier for an attacker to impersonate
a legitimate node. The nodes may not reside in physically protected places. Illegitimate nodes may
violate the routing protocol and forward packets to destinations inconsistent with the routing protocol.
Low-rate PANs such as ZigBee are highly vulnerable to jamming attacks due to their very low transmission
power [20]. A high-power-compliant transmitter could send out radio signals at the physical
layer (PHY) and weaken or eliminate the availability of a low-rate PAN.
Selective collision of some control and management frames by an adversary may appear like random
collisions and are not easily detectable. An attacker may send frames (packets) that collide with
acknowledgment of association response frames, causing an exponential back off by the sender and
restart of an association procedure.
WMNs have no central authority or trusted third party responsible for the distribution of keys that
are used for cryptography. ZigBee does make use of keys, which can be preconfigured with devices, at
different layers as well as challenge-authentication procedures.
28.4 Summary
Wireless in industrial environments is a difficult problem that requires multiple solutions and products
while at the same time enabling new applications and services and driving down costs. Security is a
paramount concern. Wireless systems provide security features such as confidentiality through AES
end-to-end encryption so sensitive data is not interpreted, integrity codes to prevent tampering with
information, non-repeating counters to prevent replay attacks, and channel hopping to minimize the
risk of denial of service attack. Industrial environments contain machinery and metal objects that present
challenges to wireless communications. Reliability and security considerations must be taken into
account before deploying applications over wireless networks.
References
1. Goleniewski, L., Telecommunications Essentials, Addison-Wesley, Boston, MA, 2007.
2. ZigBee Alliance, http://www.zigbee.org/
3. IEEE Standards, http://standards.ieee.org/getieee802/download/802.15.4-2006.pdf
4. Vlasimirov, A., Gavrilenko, K., and Mikhailovsky, A., WI-FOO, The Secrets of Wireless Hacking,
Addison-Wesley, Reading, MA, 2004.
5. Nichols, R. and Lekkas, P., Wireless Security, McGraw-Hill, New York, 2002.
6. Gast, M., 802.11 Wireless Networks, O’Reilly Media Inc., Sebastopol, CA, 2005.
7. Aime, M., Calandriello, G., and Lioy, A., Dependability in wireless networks, IEEE Security &
Privacy, 5(1), 23–29, January/February 2007.
© 2011 by Taylor and Francis Group, LLC