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Securing Fiber Using Light Polarization

Posted by timothy on from the gentlemen-sharpen-your-flashlights dept.

screenbert writes: "A new and novel way of communicating over fiber optics is being developed by physicists supported by the Office of Naval Research. Rather than using the amplitude and frequency of electromagnetic waves, they're using the polarization of the wave to carry the signal. Such a method offers a novel and elegant method of secure communication over fiber optic lines. This press release has more information. Of course I always thought that fiber was always pretty secure anyway since it's a lot harder to tap than copper."

4 of 152 comments (clear)

  1. More Secure... by jgdobak · · Score: 3, Insightful

    ...until polarizaton-based recievers become widespread, anyway.

    Security through exclusivity ("It'll be secure, because we're the ONLY PEOPLE who have the hardware to read it!") doesn't work for very long.

    Not that it's easy to tap fibers, anyway... Even if you have the equipment, you have to figure out which fiber out of 288 or more is the one you need, and the documentation is usually kept locked up tight.

    1. Re:More Secure... by jgdobak · · Score: 2, Insightful

      My point was that since the "encryption" comes along with the "signal", all you have to do is hook a "polarization-based" reciever to it to listen... No special token required.

      Hence, it'll be secure until anyone with the right dosh can get their hands on one of these recievers.

  2. Somebody explain by scott1853 · · Score: 3, Insightful

    How do you secure a physical medium from interception? If you intercept a signal, can't you just rebroadcast the same signal back out as long as it was read correctly in the first place? Isn't the real security in the encryption of the data being transmitted over the medium?

    1. Re:Somebody explain by evalhalla · · Score: 2, Insightful

      To reproduce a light polarization you have to modify it, so the one who receives the signal knows that it has been intercepted.

      Of course if you're sending unencrypted sensible informations you only know that something bad happened (which is only slightly better than something bad happening without you knowing), but if you're sending data such as the key for an encryption system you can decide whether to use it or not basing on the fact that you're sure whether it has been intercepted or not.