Location technology enhances wireless security

Increased security and reliability of enterprise-class wireless LAN technology has resulted in a greater acceptance of its use by the Utility industry. In addition, significantly reduced costs and simplified management tools, have resulted in rapidly growing deployments. What’s next? The use of wireless LAN technology to enhance overall IT security through the concept of “location-based security.”

With the advent of 802.11n and mesh technologies, wireless is beginning to provide a real alternative to wired Ethernet. For that movement to gain ground, however, Wi-Fi must offer high-level security and reliability. What safeguards are in place to prevent unauthorized access? How does a network administrator see what is “unseen”?

Standards such as Wi-Fi Protected Access 2 (WPA2) and 802.11i provide new levels of wireless security and are backed up by new monitoring and intrusion-protection tools, but enterprises increasingly are interested in the benefits of combining IT security with physical security.

It’s been difficult for enterprises to add physical security to wireless, however. How do enterprises balance providing mobility to their workers and visitors while placing needed checks on this untethered freedom?

A company, for example, may not feel comfortable letting employees access sensitive information – such as human resources, finance or new-product documents – anywhere the WLAN reaches. It might make sense to have mobility in the finance department but restrict wireless access to financial information beyond that department to prevent others from potentially seeing sensitive material.

That’s where the concept of location-based security – restricting who has access to the WLAN based on where they are – comes into play. Besides adding another layer of security, location controls – combined with access rights – can prevent overburdening segments of the network (thus preventing denial-of-service attacks) and restrict where visitors can access the WLAN.

Today’s leading WLAN switches are capable of reporting the location of laptops or mobile devices using data collected by wireless access points. These so-called “Locationing” services largely have been used for tracking assets throughout an enterprise. In hospitals, for example, they are used to locate doctors, and blood-transfusion and surgical equipment. The same technology can play a larger role in security in the form of “geo-fencing.”

Geo-fencing is a term used primarily to refer to the practice of limiting network access by mobile employees and visitors based on their geographic location and authorization status.

The user identity is established based on one or more IDs (such as an RFID-enabled visitor badge and mobile Wi-Fi device) in conjunction with a location algorithm that will determine the position of that specific ID. This will allow that person an appropriate level of network access. The basic premise is that a virtual-access “fence” is created around each mobile device and user.

This is how it works. The wireless switch “follows” a user throughout the building, granting or denying access to network resources based on the user’s authorization status and whether he’s in an area designated as approved.

The switch also ensures access to the WLAN and network resources only when the ID card (physical security) is presented with the assigned user and his mobile device. This significantly reduces the possibility of someone using another user’s laptop or mobile device to access unauthorized information on the network.

In another example of how the setup works, the wireless switch is capable of monitoring visitors and granting them access to the WLAN in a conference room where they are surrounded by other company employees, but denying access when the visitor leaves the room. Geo-fencing also can provide alerts when visitors travel outside an approved area.

Using RFID tags and readers, enterprises can record whenever a user passes through an RFID portal or reader for general asset-tracking. However, the most precise location information is obtained through a technique known as Wi-Fi triangulation. Using WLAN access points with a wireless switch that has location capabilities, enterprises can track every mobile device on the network by measuring the signal strength of transmitted packets or by pinging the devices with beacons from three or more access points.

Because most enterprise WLANs are configured to ensure optimal throughput for applications, there is usually a significant overlap among access-point coverage areas. This means that at any given location, a mobile device may be connected to a single access point, but still see and connect to nearby access points. Three access points are required to pinpoint a mobile device in a building using Wi-Fi triangulation. This method provides the location of the mobile device within 10 to 55 feet with more than 90% accuracy.

Some enterprises are combining Wi-Fi, RFID and other emerging technologies to generate even-more-detailed location information. This technique is referred to as compounding. Its basic premise is that the wireless switch analyzes both sets of data (Wi-Fi and RFID) to create a more precise location picture for each mobile device and user on the network.

The combination of IT security, physical security tools like ID cards, and real-time monitoring of mobile devices through WLANs adds a layer of defense and intelligence to any network. Geo-fencing creates a customized and invisible fence that moves with each mobile device, assuring network administrators that each device can gain access only to authorized areas and resources on the network.

It was not long ago that most Utility companies would consider WLAN technology to be a security risk itself. However, today’s enterprise-class WLAN systems have not only become as secure as the wired systems they complement but they are now being used to enhance the overall security of IT systems. It all starts with a WLAN system that has the capability of integrating other RF technologies – such as RFID – into a central management system.

Leif Eriksen is Director Energy and Utility Solutions for Motorola’s Enterprise Mobility Business.