One Way Only

Unidirectional connectivity protects airport networks using IP cameras

• By Lior Frenkel
• Sep 01, 2008

Airports are bustling international hubs, some providing services to hundreds of thousands of people from diverse locations on a daily basis. Overseeing airport security is an extremely complicated task, not just in the airport itself, but also on the airplanes.

Following the Sept. 11, 2001, terrorist attacks, a greater focus on airport security arose specifically designed to prevent terrorist activity. Naturally, technology has been harnessed to aid in this challenge. One example is the growing deployment of advanced IPbased video surveillance systems. However, one must not forget other grave security concerns in airports— ranging from air traffic control systems to securing an airport’s energy systems such as generators, air conditioning, customs and border control computers, and Xray machines.

Today, such energy centers are computer-controlled and monitored and, therefore, must be protected against cyber attacks. Technological innovations can greatly assist in providing improved security. IP-based surveillance systems have many benefits over older-generation analog and digital systems. For example, IP cameras enable on-camera automated alerting, generated in response to predefined events. Furthermore, IP-based surveillance systems allow the possibility of advanced and automatic analytics of numerous video feeds to identify predefined events, threats and fraud.

IP Advantages and Risks
Although some analytic capabilities are available as addons to analog systems, the full technological advantages are only available in IP networks, where seamless integration with additional systems provides added functionality as well as greater simplicity and efficiency.

However, when handled with insufficient attention and prudence, technology can become a double-edged sword. Despite their undisputed advantages, IP-based surveillance systems also entail grave risks that are not relevant in analog systems. When employing IP surveillance, an attacker can access a surveillance network simply by disconnecting the LAN cable of a camera—often located outside of the physical security perimeter or in an unattended location—and connecting it to a laptop. This allows access to other devices on the same network, for instance any additional cameras, surveillance servers, monitors and storage.

If the network is connected to additional airport networks, the hacker can access these networks as well. Thus, a hacker is able to cause a wide range of damage to airport security, including blocking a camera or a set of cameras, shutting down the entire surveillance system and changing or deleting stored video footage. If the surveillance network is connected to additional networks, the hacker also can interrupt IT systems across the airport.

If the access and entry control system is reached, a hacker can manipulate and operate security access controls within the airport, permitting entry to closed highsecurity zones. Where wireless technology (Wi-Fi or Wi- Max) is used to connect cameras in areas with no cable infrastructure, the hacker’s task is even easier as no physical tapping is necessary. The fact is, IP cameras function as guards but are often not sufficiently guarded themselves. The critical question then becomes who guards the guard?

The double-edged sword facet of advanced technology is well reflected in air traffic control technology as well. Naturally, the more sophisticated the means at the disposal of air traffic control personnel, the better they are equipped to coordinate aerial activity and secure airplane takeoffs and landings within their airspace. However, sophistication normally means connectivity to additional information and data sources, which in turn means greater threat exposure.

Receiving remotely generated air-traffic control video feeds is a good example of a technological advancement that has improved the air-traffic security generated with more informed and aware personnel but also has increased networks’ vulnerability by complex interconnections and distributed security responsibilities. There is no shortage of news about similar critical systems being cyber attacked or found vulnerable to such attacks when pre-emptively inspected.

Likewise, systems such as an airport’s energy center most often are remotely monitored to ensure functionality of mission- critical services. Remote monitoring, however, also entails connectivity to external sources and networks, thus exposing the monitored network to attack.

Unfortunately, it has been proven time and again that even with the use of security products such as firewalls, intrusion detection and prevention systems, there is never a guarantee of full protection against attacks because all software and logic-based solutions are vulnerable and prone to remote manipulation. Considering that airports and airplanes are some of the most lucrative terrorist targets, the premise must be that a lot of effort would be invested in order to overcome potential threats. Therefore, none of the above-mentioned solutions provide the adequate level of security required to protect airport mission-critical networks.

Unidirectional Protection
When dealing with airport security, one must deploy a powerful and absolute security solution that is not vulnerable to standard attack technologies and is immune to software flaws, bugs and, of course, human errors. To fully protect such networks, a foolproof and futureproof solution is required. Unidirectional connectivity is the only security solution that can provide full protection to such remote monitoring networks.

A unidirectional connection, also referred to as a one-way link, is a communication appliance that allows data to pass through in one direction only. Thus, video streams and camera metadata can be transferred only from a camera to the airport’s surveillance network, and not vice versa. Similarly, there would be no bidirectional connection with air traffic control networks, and thereby threats of cyber attacks would be completely eliminated. As for an airport’s energy centers, data necessary for monitoring will be passed from the energy center to the monitoring network or to third-party maintenance and control centers, but not vice versa. Therefore, once more, no online attack against the energy center would be possible.

The point in each of these scenarios is that where data must logically flow in one direction only, a unidirectional link can be implemented, enforcing strict security without impairing functionality.

Innovative Security
A secure unidirectional communication system must enforce its unidirectional data flow by means of physical hardware as opposed to software and other logical ways. The system is comprised of two hardware components that are physically capable of communicating with each other, one way only. One component can only transmit to the other, and not vice versa. This is accomplished by connecting the two components via fiber-optic cable with the transmitting component having only a transmitter—a laser LED—and the receiving unit having only a receiver—a photoelectric cell. In such a way, data can physically flow only from the transmitter to the receiver.

To facilitate reliable data transfer over a unidirectional medium, a unique communication protocol must be implemented. This protocol adds communication reliability, as well as another layer of security to the system, by allowing transfer of the payload. For example, raw video data in IP video surveillance only means stripping it from headers and other protocol fields commonly used to facilitate malicious attacks.

Based on patent-pending technology, this unidirectional connectivity concept can be implemented for securely transmitting any type of remote monitoring data, be it video streams, air traffic control data or any other type of data pertaining to remote monitoring scenarios. In every scenario, the unidirectional link will enable data to flow securely from the sensor to the monitoring network or monitoring and control center.

As the data will be flowing only one way, there will be no threat of online hacking attacks. There simply will be no return link at the hacker’s disposal.

Airport security officials should use the added advantages technology offers them when battling terrorism, crime or accidents. The solution lies with the only available foolproof and future-proof security technology—unidirectional connectivity.