Talk:Quantum cryptography

Position-based quantum cryptography

Hallo there,

I guess there is some confusion arising in using (or not using) the following terms:

"Position based quantum stuff" shouldn't take under account space-time?

Just like Global navigation satellite systems?

Or it's just me about to enter into some paradoxical conclusions?

Duh?!

Whatever... thanks for the attention anyway.

Have a nice day.

Maurice Carbonaro (talk) 08:12, 4 February 2011 (UTC)[reply]

State of the technique today?

It doesn't say what the state of the technique is today; at least not in the introduction part, and the rest of the article is just about specific parts of the technology. Shouldn't there be anything about that in the article? Is it just on the research level or is it actually being used? --Kri (talk) 16:14, 9 March 2011 (UTC)[reply]

The article does read as if the techniques are up and running everywhere, whereas much of this is still theoretical. For QKD I have added a citation needed tag to say where this can be found. Myrvin (talk) 12:39, 8 April 2011 (UTC)[reply]

Post-quantum cryptography

I have modified the entry about post-quantum cryptography. It was giving the impression that quantum cryptopgraphy could be broken by a quantum computer, which is of course not the case. The aim of post-quantum cryptography, in this usage of the term at least, is to find alternative _classical_ methods that are presumably secure against quantum computers. Quantum cryptography is obviously secure against adversaries with quantum computers, since those cannot violate the laws of quantum mechanics that are used to prove the security of QC.

Eric.cavalcanti (talk) 06:44, 18 March 2011 (UTC)[reply]

Question....

Should be explained that if Bob and Alice live at oposite parts of the earth they will need a direct optical fiber connection to actualy use QC? Security affects just the optical cable transmission.--85.52.11.16 (talk) 15:51, 6 March 2012 (UTC)[reply]

For QKD, many experiments involve photon travelling through air, if I'm not mistaken. Skippydo (talk) 04:39, 9 March 2012 (UTC)[reply]

What I think the previous user means, is that in order to preserve the quantumstate of the messages, there needs to be a direct line between Alice and Bob. If there were like a router in between, wouldn't it change the quantum stae, because it needs to repeat the message? ie. it needs to resend it to another part of the network, therefore it has to create a new message, thus losing the quantum state. This is the reason why I came here aswell, because this has been bugging me too. If someone has an answer for this? 217.150.190.17 (talk) 14:40, 6 November 2012 (UTC)[reply]

The article's content is baloney

There is no such thing as quantum crypto. Quantum computing can be used to establish a connection between points, which is what the reference to key distribution is referring to. Quantum Physics, its laws (if you want to call them this) give its users an ability to be certain that a connection between two points is just that -- and that nobody has eavesdropped on that connection.

This article ought to be removed unless robust citations are added.