Secure Video Conferencing via Quantum Cryptography

Roland Piquepaille writes "If you use a webcam to talk with your mom, this tool is not for you. But if you're working for a company and that you have to routinely discuss about sensitive future projects or the possible acquisition of another company, you need more security, and this new video conferencing system based on quantum cryptography is a tool you need. According to this article from Nature, researchers from Toshiba have developed a system which can generate 100 quantum 'keys' every second, fast enough to protect every frame in a video exchange. This technology, which today is working over a distance of about 120 kilometers, could become commercially available within two years at an initial cost of $20,000. This overview contains more details and references."

Comments

Re:THE TRUTH ABOUT ROLAND PIQUEPAILLE

[benjamin_pont]

How does this kind of thing happen? Just curious.

benjamin_pont's Recent Submissions

Title
Quantum leap in secure web video

Datestamp
Friday April 29, @02:09PM Rejected

Let's use a buzzword!

[Bender0x7D1]

There is nothing really exciting about this other than the overkill usage of quantum cryptography (also called quantum key exchange).

Basically, they are trying to generate enough keys so any succesful breaking of the cipher used gets only one frame of video. The only "exciting" part is they are using quantum cryptography to do this. However, this is like using a sledgehammer to push in a thumb tack - It uses a lot more hardware, and isn't the easiest or best method.

Another way to do this would be to conduct a large number of Diffie-Hellman key exchanges or STS exchanges, (one for each frame), and use the new key for each frame.
Or, even easier, both sides could use identical Linear Feedback Shift Registers to generate the same keys that they need. They cost way less than $20k and since a compromise of the system at either end would destroy the privacy afforded by the quantum encryption, just as secure.
Or, they could exchange one-time pads on a DVD and use the bits on there as the key. If my math is right, then a 4GB CD could hold enough keys for over 1100 hours of video, assuming a 256 bit key and 30 frames/sec. Exchanging 2 or 3 DVDs a year (if that) doesn't seem unreasonable.

None of these methods require a dedicated fiber line connecting the two groups. It can be performed over regular Ethernet if the groups want to. Translation: I can use it to talk to someone more than 120km away.

This isn't to say that some groups wouldn't want quantum security for something - if I was a Swiss bank that made daily transfers of a billion dollars to a German or Italian or French bank, then sure, I should spend the extra couple hundred k for an obscenely secure system.

This also begs the question of why encrypt each frame differently? Since it is VIDEO, then something in the picture is probably important - like a PowerPoint slide or graph or something. Since a presenter usually spends a minute or two on each slide, this means that an attacker would only need to decrypt one out of every 1800 slides (assuming 30 frames/second) to get the information they wanted. I think that it is a good idea to change keys as often as possible, but you have to ask what is the benefit for the added cost/overhead. In this case, I don't think it is very much.

So nice use of the "quantum cryptography" buzzword, but bad application of crypto technology in general.