[EMAIL PROTECTED] wrote:
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Dave Howe
Peter Fairbrother may well be in possession of a break for the QC hard
problem - his last post stated there was a way to clone photons with
high accuracy in retention of their polarization
I promised some links about the 5/6 cloning figure. You've had a few
experimental ones, here are some theory ones.
Cloning machines:
http://www.fi.muni.cz/usr/buzek/mypapers/96pra1844.pdf
Theoretically optimal cloning machines:
http://www.gap-optique.unige.ch/Publications/Pdf/PRL02153.pdf
1/6
I'm always stuck on that little step where Alice tells Bob what basis
she used for each photon sent. Tells him how? They need integrity
protection and endpoint authentication for N bits of basis. Is the
quantum trick converting those N bits to N/2 privacy-protected bits
really as
I always understood that QKD is based on a hard problem of which the theory of
physics says it is impossible to find a solution (if not, then i'd like to
know). Then if QKD breaks, the current theory of physics was wrong.
On the other hand, if DH or RSA breaks, factoring or the discrete log turn
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Dave Howe
Peter Fairbrother may well be in possession of a break for the QC hard
problem - his last post stated there was a way to clone photons with
high accuracy in retention of their polarization
[SNIP]
Not a break at all. The
[EMAIL PROTECTED] wrote:
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Dave Howe
Peter Fairbrother may well be in possession of a break for the QC hard
problem - his last post stated there was a way to clone photons with
high accuracy in retention of their polarization
BTW, you can decrease the wavelength of a photon by bouncing it off
moving
mirrors.
Sure. To double the energy (halve the wavelength), move the mirror at
70% of the speed of light. And since you don't know exactly when the
photon is coming, keep it moving at that speed ...
At 6:38 PM -0400 9/18/03, John S. Denker wrote:
Yes, Mallory can DoS the setup by reading (and thereby
trashing) every bit. But Mallory can DoS the setup by
chopping out a piece of the cable. The two are equally
effective and equally detectable. Chopping is cheaper and
easier.
Other
There are lots of types of QC. I'll just mention two.
In classic QC Alice generates polarised photons at randomly chosen either
+ or x polarisations. Bob measures the received photons using a randomly
chosen polarisation, and tells Alice whether the measurement polarisation he
chose was + or x,
On Sun, Sep 21, 2003 at 01:37:21PM +0100, Peter Fairbrother wrote:
[cloning photons]
There is also another less noisy cloning technique which has recently been
done in laboratories, though it doubles the photon's wavelength, which would
be noticeable,
To get rid of the wavelength change it
Date: Fri, 19 Sep 2003 11:57:22 -0400
From: Ian Grigg [EMAIL PROTECTED]
If I understand this correctly, this is both
an eavesdropping scenario and an MITM scenario.
In the above, Eve is acting as Mallory, as she
is by definition intercepting the bits and re-
sending them on?
As Dave
QC is currently a one-time pad distribution mechanism - or at lower rates a
key establishment mechanism most suitable for symmetric algorithms.
You are correct that authentication is not inherent. Then again, this is
also true for classical symmetric and PKI schemes. To be usable, all
crypto
martin f krafft wrote:
So MagiQ and others claim that the technology is theoretically
unbreakable. How so? If I have 20 bytes of data to send, and someone
reads the photon stream before the recipient, that someone will have
access to the 20 bytes before the recipient can look at the 20
Arnold G. Reinhold wrote:
I think there is another problem with quantum cryptography. Putting
aside the question of the physical channel, there is the black box at
either end that does all this magical quantum stuff. One has to trust
that black box.
- Its design has to thoroughly audited and
martin f krafft wrote:
So MagiQ and others claim that the technology is theoretically
unbreakable. How so? If I have 20 bytes of data to send, and someone
reads the photon stream before the recipient, that someone will have
access to the 20 bytes before the recipient can look at the 20
bytes,
On 09/13/2003 05:06 PM, David Wagner wrote:
Quantum cryptography *assumes* that you
have an authentic, untamperable channel between sender and receiver.
Not true. The signal is continually checked for
tampering; no assumption need be made.
Quantum crypto only helps me exchange a key
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