MP_UK 12/4/2012 | 10:04:46 PM
re: Quantum Cipher Sent by Fiber
If anyone is interested in further reading on the subject of cryptography, I recommend "The code book" by Simon Singh. Not too in-depth but very interesting....
facetious 12/4/2012 | 10:04:47 PM
re: Quantum Cipher Sent by Fiber OK, got it!

Thanks, /f
fusionboy 12/4/2012 | 10:04:59 PM
re: Quantum Cipher Sent by Fiber No - for the same reason you can't use regeneration equipment.

I won't go into QMechanics here, but simply put, by observing the message, you change the message - which is why QCryptography is unbreakable.

facetious 12/4/2012 | 10:05:17 PM
re: Quantum Cipher Sent by Fiber Couldn't you just intercept the key transmission if you cut the fiber & put your own equipment on it, and then send the signal on to the intended receiver?

Oakster 12/4/2012 | 10:05:18 PM
re: Quantum Cipher Sent by Fiber ...the system has a distance limitation of around 70 km, because of the attenuation in optical fiber.

Hmm... I'm sure 70km is probably far enough for use in Switzerland.

It's not possible to send the key through Erbium Doped-Fiber Amplifiers (EDFAs), which would alter the physical properties of the optical signal.

So much for the rest of the world.

Now if those Swiss could only figure out how to avoid busy signals when someone frantically tries to call the control tower in Z++rich...
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