Re: Quantum cryptography tackles video


Baugh wrote:
> Schoenfeld wrote:
> > Baugh wrote:
> >
> >>Jan Panteltje wrote:
> >>
> >>>On a sunny day (Wed, 11 May 2005 03:37:45 GMT) it happened Sam
> >
> > Wormley
> >
> >>><swormley1@xxxxxxxxx> wrote in <d6fge.73586$c24.66093@attbi_s72>:
> >>>
> >>>
> >>>
> >>>>Quantum cryptography tackles video
> >>>> http://physicsweb.org/articles/news/9/5/5/1
> >>>>
> >>>>10 May 2005
> >>>>
> >>>>Physicists at Toshiba have used quantum cryptography to transmit
> >
> > voice
> >
> >>>
> >>>Yes, it was discussed in sci.crypt weeks ago, and it is useless,
as
> >
> > it
> >
> >>>requires a glassfiber between receiver and transmitter, and STILL
a
> >
> > man in
> >
> >>>the middle can fake it.
> >>>So you need a reel of fiber, and a shovel, and a permit to open up
> >
> > every
> >
> >>>street etc...
> >>>
> >>
> >>You are mistaken. The point of quantum crypt. is that should the
man
> >>in the middle read the signal he will affect it. You can't
> >
> > anonymously
> >
> >>tap a quantum signal.
> >
> >
> > Quantum Cryptography will only be used for secure key exchange.
It's
> > still not 100% secure.
> >
>
>
> Yes but with a quantum crypto line you can send arbitrarily large
keys
> with assurance that they have not been intercepted. Hence via
*private*
> key encryption you can get as close to 100% secure as possible.
> Of course this will help naught if the people at the end points are
> given a big enough bribe.

There's another fundamental problem which I have not seen discussed
anywhere. The only practical benefit of a quantum line is that the two
parties can detect evesdroppers (since the evesdropper affects the
polarity of the transmitted photons). Thus the idea is that the
communicating parties won't transmit data over the classical line if
they detect an evesdropper on the quantum line (since the advesary
would know the key and thus be able to decrypt the data).

But this protocol allows advesaries to simply packet sniff the quantum
line for the intent of preventing communications between the two
parties.

Whats worse, private communications exposed to advesaries or advesaries
preventing private communications completely?

> So the endevor is worth while. It is IMNSHO all the practical
benefit
> we will get out of the domain of "quantum computing". But that is a
> guess on my part.
>
> Regards,
> James Baugh

.

Relevant Pages

  • Re: Quantum cryptography tackles video
    ... >>> But this protocol allows advesaries to simply packet sniff the ... >>> line for the intent of preventing communications between the two ... >>> preventing private communications completely? ... >to jam a quantum line than a classical line. ...
    (sci.physics)
  • Re: Quantum cryptography tackles video
    ... >> to jam a quantum line than a classical line. ... > consider the annual effect the illegal drug trade has on the US. ... > James Baugh ... quantum lines with relative ease then they most assuredly will. ...
    (sci.physics)
  • Re: Quantum cryptography tackles video
    ... >> But this protocol allows advesaries to simply packet sniff the ... >> line for the intent of preventing communications between the two ... to jam a quantum line than a classical line. ...
    (sci.physics)
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