Declassified: The US Government’s Quantum Internet
theconnectivist.com
theconnectivist.com
Trusted node networks are a viable option for corporations. Indeed, several European banks are already using IDQuantique turnkey systems, as mentioned in the article. These networks are not viable for private individuals, especially those who are not comfortable with entrusting their plaintext to the operator(s) of the trusted nodes.
There are ways to build quantum repeater networks that do not require the use of trusted nodes, but these remain experimental because some of the underlying technologies needed to overcome distance limitations in such networks (e.g. Quantum memories) are still in their infancy. The quantum smart cards in this article do not even attempt to address this.
Corporations interested in building a private trusted node quantum network similar to IDQuantique's offerings may want to look into these quantum smart cards. They are wildly inappropriate for civilian use however. Even plugging in directly to your local bank would require you to have a direct fiber link to a node under the control of that bank. This would be prohibitively expensive.
See http://www.youtube.com/watch?v=UVzRbU6y7Ks for the quantum key exchange protocol. The protocol doesn't need a quantum back-channel. What has been "declassified" about this approach?
Whenever you purchase something online and you hit the ‘buy’ button and your computer seems to buffer, taking its sweet time to present you with the order confirmation page and you begin to doubt that the order went through successfully, “that’s because of the cryptography,” says Hughes. It takes time to create a secure line to transmit sensitive information, like your card number, between your laptop, eBay, and your bank. But “in our case that just wouldn’t happen,” says Hughes, “in principle [our invention] could speed up the Internet.”
Bad journalism. That quote is probably taken way out of context. Website delays usually have very little to do with cryptography, and everything to do with the web apps and backend databases or credit card processors being slow to process orders. The slow part of SSL encryption (key exchange) isn't that slow, and is probably already done before you submit an order, if the site uses a ssl session cache.
And bad comment :-/
Nothing personal, this is intended as constructive criticism.
You completely ignore the main point of the article, and come quibbling about an unrelated detail.
This kind of comment often ends up at the top of the comment thread and obscures the comments that discuss the subject matter.
Your point is rather obvious, and I suppose that you end up being upvoted by folks not knowledgeable enough to discuss TFA, but feel validated by the fact that they also spotted the error.
The article is about quantum cryptography. The author gives credit card processing as a layman example of encrypted communication, and states, erroneously, that the connection process is slow because of the SSL handshake.
It is true that SSL increases latency, but it is not the main factor, as harshreality said.
However, the example is an aside, and the error is a small aside in the aside. Not really worth discussing, and it definitely doesn't have its place at the top of the thread, where it was when I first posted. It is still currently the second comment.
Note that harshreality improved his post after the fact... or did I miss the good bits when I first read it? Hoist with my own petard? If so, sincere appologies.
https://news.ycombinator.com/item?id=5661576
http://arxiv.org/abs/1305.0305?utm_source=feedly
Read the arXiv paper: it's quite short and not very technical. The BB84 protocol used is described in a lower comment by 'harshreality. It is secure against any purely classical attacker; Preskill and Shor give a (highly involved) proof of security here:
http://arxiv.org/pdf/quant-ph/0003004
However, the BB84 protocol used is susceptible in its original form to quantum man-in-the-middle attacks, eg:
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=523467...
LANL probably thinks this is infeasible at the moment -- with good reason: quantum computing equipment is extraordinarily difficult to obtain or produce, and so it would be very hard indeed to carry out such an attack in secret. There are approaches to dispelling quantum MitM, such as a paper I've posted below.
it's a star (radial) topology, with quantum links outwards only, which is enough to distribute keys. end nodes only need quantum receivers so it's cheaper than bi-directional systems.
Not so sure about this one. As long as you have humans in charge, episodes like the Edward Snowden affair will continue to occur.
2. Quantum nondemolition measurements have been used to detect macroscopic objects with a vanishing probability of interaction. There is a good chance the approach can be adapted to detect photons, breaking quantum crypto.
Basically, quantum crypto is at best snake oil and probably worthless.
False. See e.g. "Quantum protocols for the millionaire problem are trivial", He 2012
http://arxiv.org/pdf/1207.6739
> Quantum nondemolition measurements have been used to detect macroscopic objects with a vanishing probability of interaction. There is a good chance the approach can be adapted to detect photons.
Interaction-free measurement has certainly been demonstrated, but it doesn't do what you think it does. It is provably impossible to measure a state without forcing it to be expressed in the basis of measurement, but this is not the same thing as interaction. I.e. if you measure the position of a particle, you will always find it has a definite position, but you cannot find that it was previously in a state without a definite position. See:
The main point of quantum crypto deployments (at least now) is to protect against future offline attacks (possibly using quantum computer). So in practice, I don't believe these authentication schemes are deployed.