eyeEven if you have read our previous posts on data security and encryption, your computer data is probably still at risk. Scientific American recently reported on a variety of “side-channel” data vulnerabilities–threats of data theft through passive or mechanical means that bypass your software and operating system altogether.

Below are five frightening new ways to steal the data on your computer:

1. Reading data from the reflection on your eyeball

New techniques involving telescopes and cameras are now able to capture computer data from monitor reflections on eyeballs, glasses, and office picture frames.

2. Stealing data from your monitor’s radio emissions

Computer monitors radiate low-voltage signals from their power cords which allow people with sophisticated monitoring equipment to capture and reassemble the images on your monitor.

3. Capturing network data from the flashes on a router

The constantly-flashing LED lights on network routers can be recorded to capture the data bits traveling through them. These patterns can be reassembled to decipher communications going through the router.

4. Copying printer data from the sound of the printer head

Some printers — especially the old dot matrix variety — make small noises as they move across your paper. These sound frequencies are slightly unique depending on what movement the printer head is making. By recording the sound waves of a printer, special algorithms can decipher the text being printed.

5. Learning your passwords from the radio frequency of your keyboard

Similar to capturing the electronic frequencies emitted by monitors, keyboards emit unique low-voltage radio frequencies with each keystroke. Basic radio-frequency monitors can be combined with capture software to copy anything typed. Check out this video of keystroke theft in action:

Thankfully, at this point these data invasion methods are seldom-used. However, for that reason, there also are few countermeasures or security products on the market to prevent espionage through these side-channel methods. While it is unlikely most attorneys need to worry much about these vulnerabilities, anyone with especially-secure client or corporate data should at least spend a few minutes thinking about whether they could present real threats.

How Hackers Can Steal Secrets from Reflections | Scientific American

(photo: annieominous)


  1. I think those guys at Scientific American spend too much time watching Mission Impossible reruns at 3 a.m. If they got out of the house more, they’d realize no one uses a dot matrix printer anymore.

    Seems like the nerds’ version of fantasy football. It would be easier to just kidnap people and torture them for their passwords.

  2. Aaron Street Aaron Street says:


    I would agree that for 99.5% of people none of these things are currently worth worrying about.

    That said, corporate espionage is a MAJOR issue for companies with valuable IP and some of these methods would be easy to employ without raising security alarms.

  3. Sam Glover Sam Glover says:

    I would characterize these methods of data theft as “awesome” rather than “shocking.”

    And hey, if someone wants to sneak into my office, replace my desktop and monitor with a laptop, stick a radio frequency sniffer nearby, and hope I don’t notice, they are welcome to try. I will amuse myself by typing crude phrases until I get bored, and then point the radio frequency sniffer at the coffee maker.

  4. Eric says:

    Aaron, can you provide sources for your information regarding issue 2 & 3. Thanks. And thanks for the interesting article.

  5. Aaron Street Aaron Street says:

    Eric – The source for the entire post was the article in Scientific American I linked to at the bottom.

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