July 6, 2007The Homeland Security Department's planned wireless network of high-tech towers to watch for illegal immigrants crossing the border from Mexico into the United States is vulnerable to cyberattacks that could shut the system down, according to security experts.
The Secure Border Initiative Network (SBInet) surveillance system, a network of 1,800 towers housing infrared cameras, radar and communication equipment along the U.S.-Mexican border that DHS just began testing, will use commercial wi-fi systems to connect the towers to command-and-control centers operated by U.S. Customs and Border Protection and to computers in vehicles operated by border agents. (See "Vast Expanse," Government Executive, April 1.)
In September, DHS awarded Boeing the SBInet contract, which is worth an estimated $2.5 billion. Last month, the company initiated a pilot project to test nine 98-foot towers spanning 28 miles of the border southwest of Tucson, Ariz. But shortly after the towers went up in mid-June, they started knocking out wireless Internet service in Arivaca, Ariz., a town of about 1,500 residents located 12 miles north of the Mexican border.
Allan Wallen, who runs a wireless Internet service provider cooperative serving Arivaca, sent Boeing a series of e-mails about the problem. He said the company confirmed it was using the 5.8 gigahertz wi-fi band (also known as industry standard 802.11a) for communications on the SBInet towers -- the same frequency the ISP used to provide Internet service.
Using standard commercial 5.8 gigahertz wi-fi equipment could leave SBInet open to intentional interference. "A drug dealer could buy a laptop with built-in 5.8 gigahertz wireless and could launch a denial of service attack against SBInet," Wallen said. He said he could detect that the SBInet wireless network used a strong form of encryption, Wi-Fi Protected Access. But the encryption would not be useful in stopping denial of service attacks, said Wade Williamson, director of product engineering for AirMagnet, which sells wireless intrusion detection systems.
Williamson said mounting a denial of service attack against a wi-fi network is a "trivial exercise" because even on an encrypted network, the address of an end user device or wi-fi access point -- known as a media access control address -- is clearly broadcast and retrievable. Anyone who wants to knock out the transmissions from the SBInet towers could capture that address, spoof it and then flood a tower or end user with data packets, Williamson said. He added that SBInet communications also could be jammed by inexpensive signal generators that could knock out the signal from the towers.
An intrusion detection system would help DHS and Boeing detect such cyberattacks and zero in on the location of intruders by triangulation, Williamson said. DHS and Boeing could also "fight fire with fire" by launching reverse denial of service attacks, he said.
George Teas, director of field engineering for Fortress Technologies, which sells wi-fi systems hardened with multiple layers of security for government users, said his company provides multifactor authentication systems that include a unique device identifier, which insures that even if hackers spoof a media access control address, they will not be able to get into a network. An attacker would not be able to take down all of the SBInet with a denial of service attack, Teas said, but just one node with traffic routed around that node.
Boeing referred all questions to Customs and Border Protection. CBP officials did not respond to a query on the security of the SBInet wireless system.
Boeing evidently is looking to increase security for the next phase of SBInet. Teas said Fortress just responded to a request for proposals from Boeing for a secure wireless network. Boeing wants jam resistant wi-fi equipment that also has low probability of detection and interception, according to a data sheet on Boeing's SBInet business opportunities Web page.
As for Arivaca's Internet service, Boeing told Wallen in an e-mail that it had stopped using frequencies used by the ISP cooperative to eliminate interference. Wallen said he has less interference than when Boeing first turned on the Arivaca tower, but he said his network still experiences interference if the SBInet wireless network periodically switches frequency channels.
July 6, 2007