“Security Cameras”

By Scott Hamilton

Have you ever heard the term oxymoron? It is a figure of speech in which apparently contradictory terms appear together, for example the organized chaos of democracy.

A study out of Northeastern University proves that security cameras are an oxymoron. We all tend to think that the increase in the number of security cameras around us has made the world a safer place. However, this particular group of researchers claims that the cameras themselves create an added security risk.

Kevin Fu, professor of electrical and computer engineering at Northeastern has figured out a way to eavesdrop on most modern cameras. He developed a rather simple technology called EM Eye, short for Electromagnetic Eye, which is a technique for remotely viewing the video from another person’s camera through walls in real time.  The really scary part is that it works on some cameras even when the camera is not in use. EM Eye redefines the idea of a Peeping Tom.

According to the research anyone with a few hundred dollars worth of equipment, a radio antenna and a little engineering know-how can recreate his research. Fu says, “With your typical security camera, on the inside there’s a camera lens and then there’s got to be something else on the inside, like a computer chip, that’s got a wireless connection back to the internet. There are wires between two different chips inside [these cameras], and those wires give off electromagnetic radiation. We pick up that radio, and then we decode it, and it just happens to be that we get the real-time encoded video.”

So let me try to explain this in simple terms. The camera consists of a lens, a digital sensor and  a video processor. There are wires running from the digital sensor to the video processor. On most cameras, including the one in your cell phone, these wires are more than an inch long. These wires create an antenna of sorts that broadcasts a very weak radio signal. There is an industry standard that specifies the frequency of this signal and the way the image is encoded. This means there is nothing secret here. Anyone with the ability to understand the video encoder specification can read and understand the raw signal from the camera sensor.

Using a good antenna and a simple amplifier to increase the strength of the signal, you can recreate the video on a remote device. Not by hacking the phone, camera, or the internet connection of the device. Not even using the encrypted video from the camera, but the raw information coming from the sensor itself. This makes it possible to capture the video in real time, just like the local video processor on the camera or cell phone.

During Fu’s experiments he was able to capture raw live video from several modern security cameras and cell phone cameras through walls and up to fifteen feet away from the device. He has not yet attempted to capture the audio signals from the camera that take a similar path, but my belief is that audio would be more difficult. The reason audio is more difficult is because there is not an industry standard for the transfer of raw audio between a microphone and sound capture device. Also the sound capture chip usually takes in the analog audio signal and does the conversion to digital within the device, making the standard digital signal way too small to capture. The wires inside the audio chip are shorter than the thickness of a human hair, meaning there is no significant broadcast of the audio signal.

Regardless of the level of effort camera manufacturers have put into securing the intentional digital signals from the camera, they did not put enough thought into the leakage of information through unintended channels. They never intended the wire from the camera to the video encoder to become a radio transmitter, but unfortunately it is. The leaky radio in the wire is not the biggest problem uncovered by the research, but it is the fact that if the camera sensor is powered on, it is broadcasting the signal, even if the camera application is not displaying the image. For example if you are on a zoom call and check the box to not show the camera, the camera sensor is still sending signals to the video encoder and Fu’s technique can still view images from your camera.

As I have stated many times in the past, the only secure electronic device is the one powered off, disconnected from the power source, and locked in a safe. If you want to make sure no one is spying on your camera, about the only way to do it is to cover the sensor. Just make sure that it is covered with a material that will not allow any light to pass through.

Until next week, stay safe and learn something new.

Scott Hamilton is an Expert in Emerging Technologies at ATOS and can be reached with questions and comments via email to sh*******@te**********.org or through his website at https://www.techshepherd.org.