[10743] in cryptography@c2.net mail archive
Quantum crypto broken?
daemon@ATHENA.MIT.EDU (Michael_Heyman@NAI.com)
Sun May 12 21:38:26 2002
Message-ID: <DBF2F9C6F6BAD211BB1B00A0C99D9702AFC5F8@GLE-77-205.nai.com>
From: Michael_Heyman@NAI.com
To: cryptography@wasabisystems.com
Date: Fri, 26 Apr 2002 09:36:22 -0500
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Would anybody with more knowledge care to comment on this?
This article leads one to believe that one can eavesdrop without being
detected and with nearly 5/6ths confidence of the data on a quantum =
crypto
communication. This is in contrast to the claim to fame of quantum =
crypto
that the receiver will know if there is an eavesdropper. (This is what =
makes
quantum crypto work when all public key crypto gets broken.)
Quantum crypto has "1 photon"=3D"1 bit" with the polarization of the =
photon
giving the 1 or 0 of the bit.
It seems photon polarization state can be duplicated with nearly 5/6th
confidence.
From:
<http://physicsweb.org/article/news/6/3/21>
Near-perfect copies of single photons have been made in=20
the lab for the first time...
The Oxford team sent a photon from one such pair [of=20
entangled photons] into an optically active crystal=20
where it stimulated the emission of a further photon.=20
There is an increased chance that the new photon will=20
have the same polarization as the 'input' photon. In=20
contrast, photons that are emitted spontaneously are=20
equally likely to be in either polarization state.=20
There is also an abstract at:
<http://www.sciencemag.org/cgi/content/abstract/1068972v1>
Experimental Quantum Cloning of Single Photons=20
Ant=EDa Lamas-Linares, Christoph Simon, John C. Howell,=20
Dik Bouwmeester=20
-Michael Heyman
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