By Nicholas Sheble
“The technologies of Wi-Fi, Bluetooth, and WirelessHART/ISA100.11a are well known and thus, security is an absolute must,” Ira Sharp warned a group of wireless forum attendees late last week.
Sharp, lead product specialist — industrial wireless products at Phoenix Contact, and other presenters at the company’s Industrial Wireless Forum 2010 in Houston late last week, are confident wireless technologies that monitor and control industrial process applications are safe, reliable, and secure.
Sharp will present a webinar entitled “Network Security in a Wireless World” Nov. 18. Click here to register for the event.
Wi-Fi technology has spread widely within business and industrial sites. In these environments, increasing the number of Wi-Fi access points provides network redundancy, support for fast roaming and increased overall network-capacity by using more channels or by defining smaller cells.
Many see IEEE 802.11 as interchangeable with Wi-Fi. It allows the deployment of local area networks (LANs) without wires reducing the costs of network deployment and expansion.
Manufacturers are now building wireless network adapters into the ubiquitous laptop. The price of chipsets for Wi-Fi continues to drop, making it an economical networking option and widespread in corporate infrastructures.
Bluetooth is an Ericsson-created, open wireless technology standard for exchanging data over short distances using short wavelength radio transmissions. We can use it with fixed and mobile devices and create secure personal area networks. It was originally a wireless alternative to RS-232 data cables. It can connect several devices while avoiding problems of synchronization.
WirelessHART is a wireless networking technology developed by HART Communication Foundation. The protocol utilizes a time synchronized, self-organizing, and self-healing mesh architecture. The protocol currently supports operation in the 2.4 GHz ISM band. It is a wireless standard and is specifically for the requirements of process field-device networks.
“External attacks on a network system include eavesdropping, active eavesdropping like “man-in-the-middle,” brute force attacks like denial-of-service, and spoofing are some of the dangers,” Sharp said.
A man-in-the-middle attack is active eavesdropping in which the attacker makes independent connections with the victims and relays messages between them, making them believe they are talking directly to each other over a private connection, when in fact the attacker controls the entire conversation.
Internal problems exist in the form of worms, viruses, and like malware that thumb drives sometimes spread when connecting to the company network whether inadvertently or intentionally.
As well, unauthorized access or even accidental access to the system such as when an engineer connects to the wrong PLC can cause distress to the operation.
“Network risks mean loss of time, lost production, lost money,” Sharp said. “There may be environmental damage and loss of compliance with governmental constructs like those from the EPA, OSHA, or the FDA.”
“Damage to the corporate image is also possible,” Sharp said.
Part of the answer and security for the system is different layers of protection and security. This includes encryption and authentication.
Encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing “the key.” Encryption, by itself, can protect the confidentiality of messages and data transmission, but other techniques are necessary to protect the integrity and authenticity of a message.
Verification of a message authentication code or a digital signature is a good idea, too. Standards and cryptographic software and hardware to perform encryption are widely available.
WPA2 (IEEE 802.11i) is the industry standard now.
IEEE 802.11i supersedes the previous security specification, Wired Equivalent Privacy (WEP), which had security weaknesses. The Wi-Fi Alliance then introduced Wi-Fi Protected Access (WPA) as an intermediate solution. Now the Wi-Fi Alliance refers to their approved, interoperable implementation of the full 802.11i as WPA2, or RSN (Robust Security Network). It uses the Advanced Encryption Standard (AES) block cipher, whereas WEP and WPA did not.
“But security is only half the battle,” Sharp said. He further recommends:
• Firewalls, one big firewall isn’t enough
• Segment your control network from other information networks
• Ask questions about incoming and outgoing data
• Control who has access to what and what levels of access are necessary for folks to do their jobs
• Employees who leave the company, remove their access
• Practice defense-in-depth, the information assurance strategy in which multiple layers of defense are throughout an information technology system
The defense-in-depth strategy, originally coming out of the National Security Agency, is critical.
Using more than one of the following layers constitutes defense-in-depth:
• Physical security (e.g. deadbolt locks)
• Authentication and password security
• Hashing passwords
• Anti virus software
• Firewalls (hardware or software)
• DMZ (demilitarized zones)
• IDS (intrusion detection systems)
• Packet filters
• VPN (virtual private networks)
• Logging and auditing
• Timed access control
• Software and or hardware not available to the public, aka security through obscurity
You can contact Nicholas Sheble at email@example.com.
By Nicholas Sheble