from the what-an-entangled-web-they-weave dept.
In the race for safer ciphers, China just quantum-leap frogged the rest of the world.
[...] Now, China aims to escape that contest entirely with the creation of a communication network not secured by math, but guaranteed by the fundamental rules of nature. A team has demonstrated mastery over the secret sauce behind such a "quantum internet" with their satellite Micius, which recently smashed the distance record for creating a bizarre link between light particles known as entanglement.
"They are years ahead of everyone else in this technology," says Vadim Makarov, head of a quantum hacking lab at the University of Waterloo in Canada, who was not involved. "It's absolutely awesome."
Launched August 2016, the Micius satellite successfully entangled photons between two Chinese towns almost 750 miles apart. The experiment bested former fiber-optics setups by a factor of 10, a feat chief architect Jian-Wei Pan says others dismissed as "a crazy idea" when he first proposed it back in 2003. The accomplishment proves possible the ultimate aim of cryptography: an invincible code system theoretically capable of instantly connecting any two (or more) points on Earth.
No Man-In-The-Middle for you!
Related Stories
Quantum Satellite Links Extend More Than 1,000 Kilometers
A space-based, virtually unhackable quantum Internet may be one step closer to reality due to satellite experiments that linked ground stations more than 1,000 kilometers apart, a new study finds.
[...] In 2017, scientists in China used the satellite nicknamed Micius, which is dedicated to quantum science experiments, to connect sites on Earth separated by up to roughly 1,200 kilometers via entanglement. Although those experiments generated about 5.9 million entangled pairs of photons every second, the researchers were able to detect only one pair per second, an efficiency rate far too low for useful entanglement-based quantum cryptography.
Now, the same researchers have achieved their goal of entanglement-based quantum cryptography using the Micius satellite. The scientists, who detailed their findings [DOI: 10.1038/s41586-020-2401-y] [DX] online in the 15 June edition of the journal Nature, say they again connected two observatories separated by 1,120 kilometers. But this time, the collection efficiency of the links was improved by up to four-fold, which resulted in data rates of about 0.12 bits per second.
The scientists employed two ground stations, in Delingha and Nanshan, in China. Each site had a newly built telescope 1.2 meters wide that was specifically designed for the quantum experiments.
To boost the efficiency of the quantum cryptography links, the researchers focused on improving the systems used to acquire, orient toward and track targets at both the satellite and ground stations. They also made sure to improve the receiving and collection efficiencies of the lenses and other optical equipment on the ground.
Also at New Scientist and NYT.
Previously: China's "Quantum-Enabled Satellite" Launches
China's Quantum Communications Satellite Beats Record
Unbreakable: China Doubles Down On Quantum Internet
Quantum Video Chat Links Scientists on Two Different Continents
Why This Intercontinental Quantum-Encrypted Video Hangout is a Big Deal
Related: Quantum Ghost Imaging Spy Satellites
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @03:07AM (8 children)
What will the government do once that gets out in the wild? Let's hope they can't stop it. Internet liberation is at hand!
(Score: 2) by c0lo on Wednesday August 09 2017, @03:11AM (7 children)
Mmmm... aren't you forgetting the setup cost?
What will you do? 'Cause I doubt you'll be able to 3D-print your own "photon entangler" on your personal RepRap printer.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @03:14AM (6 children)
We're going to need to science the shit out of this!
Well, granted, it's not as convenient as asymmetric key cryptography. You'd have to physically exchange something (entangled photons) with the other party I'm assuming. IANAQuantumPhysicist.
(Score: 4, Informative) by maxwell demon on Wednesday August 09 2017, @04:33AM (5 children)
Sort of. You definitely have to exchange entanglement, but it can be mediated by a third party (or a whole set of them).
Indeed, for entanglement distribution the following model can help (note that it is not an accurate model of entanglement; it just shares enough properties to explain how entanglement distribution works):
Imagine the entangled pair as two sealed boxes containing the same one-time pad. You've got a mechanism that locally creates such a pair of boxes (that is, creates a new, random one-time pad and puts it into two of the sealed boxes). You also have mechanisms to flip bits in the box, and you've got a mechanism that takes, locally, two boxes, calculates the XOR of their pads, which it outputs in the clear, but deletes the codes in the boxes while doing so. What you cannot do is to read out the pad of a single box.
Now if you want to share an entangled pair (that is, two boxes with the same one-time pad) between Alice and Bob, then the obvious way to do so is that e.g. Alice uses the creation mechanism to create a pair of boxes, and sends one of the two boxes to Bob. However there's also another way, "pad swapping" (the model equivalent to entanglement swapping): Alice and Bob can send both boxes to Charlie, who uses the second mechanism to get the XOR. then he sends the clear-text result to Alice and/or Bob. Since the XOR data tells them which bits differ, they can use it to flip those bits in one of the boxes. By doing so, they again have two boxes with the same pad. Note also that the XOR data does not reveal anything about that shared pad.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by FatPhil on Wednesday August 09 2017, @07:49AM (3 children)
Which will be pointless, those boxes no longer containany thing but noise, and flipped noise is still noise.
If you want quantum key exchange, I recommend doind it in perl: http://fatphil.org/crypto/QKE.html
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Interesting) by maxwell demon on Wednesday August 09 2017, @09:03AM (2 children)
The boxes Charly has (one from Alice and one from Bob) will contain noise. The boxes Alice and Bob retained are not altered by Charlie's application of the XOR mechanism. And it is one of those boxes where the bit flips would be applied.
For example:
Here the digit strings in square brackets (like [0101]) denote the boxes, while strings without boxes denote open information (i.e. the result of Charlie's XOR mechanism application). As you can see, in the end, Alice and Bob share a pair of "entangled" boxes (boxes with the same content).
Note: The colons above are to work around an apparent bug in the ecode tag, which seems to switch to a proportional font on an empty line:
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by number6 on Wednesday August 09 2017, @10:28AM (1 child)
To have a whitespace line use & n b s p ; (https://en.wikipedia.org/wiki/Non-breaking_space)
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @12:22PM
While that's a less visible workaround, it's still a workaround. It shouldn't be needed.
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @04:03PM
Thanks! I didn't know about entanglement swapping. I'll have to digest that some.
(Score: 3, Insightful) by c0lo on Wednesday August 09 2017, @03:08AM
For you, it always will be The (China) Man in the middle - he's owning the operational infrastructure - if you don't want him in the middle, there's no access for you.
The correct quip: "No Man-In-The-Middle for The Man"
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by kaszz on Wednesday August 09 2017, @03:28AM (5 children)
Seems China provided the ultimate way to bypass their own firewall:
Other uses could be Gamma-ray burst (GRB) detection satellites.
Two questions:
* What does it takes to build a quantum link?
* Cost?
Meanwhile in America the most important issue is whether Google employees can even hint that they are not fully diversified and if Trumps cat likes Russky caviar or stressed out McPig. Got to have the priorities right!
(Score: 2) by c0lo on Wednesday August 09 2017, @03:31AM (4 children)
Calling @realDonaldTrump to #MAGA this!
(grin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by kaszz on Wednesday August 09 2017, @03:40AM (3 children)
Note that you may only call using a diversity certified phone through the diversity management engine! :-)
(Score: 2) by Sulla on Wednesday August 09 2017, @03:45AM (2 children)
I can't tell whether or not this post is committing workplace violence, it has a "you" but did not first ask if I, the reader, is okay with that. I am going to go ahead and file a report anyways and let managemnt deal with it.
Ceterum censeo Sinae esse delendam
(Score: 1, Funny) by Anonymous Coward on Wednesday August 09 2017, @10:25AM
Well, the word "you" is connected with "may", which means the poster implies himself to be in a position where he can decide to say what you may or may not do, that is, in a position of power over you. In other words, he's clearly oppressing you. A clear case of workplace violence. ;-)
(Score: 2) by hendrikboom on Wednesday August 09 2017, @05:34PM
I was recently at a talk on the use of personal pronouns in Japanese. The speaker told of a Japanese family who found the proper use of "you" so socially difficult that for their entire existence as a family they never used any form of that pronoun tp refer to each other. They wanted to avoid being overly familiar, insulting, formal, standoffish, whatever. So best just to avoid the pronoun altogether.
(Score: 2) by driverless on Wednesday August 09 2017, @03:39AM (5 children)
That's not how "quantum cryptography" works. The very fact that the article talks about "safer ciphers" shows that the author doesn't understand it. It's a cool physics project, not anything to do with security. Every few years, someone posts a new record achieved, just like people announce being able to send a WiFi signal 200km using a dish the size of a small house on a mountaintop, or run/swim/cycle over X distance faster than anyone else. Congratulations China, have a biscuit, we'll wait for the next record in a year or two.
(Score: 2) by FatPhil on Wednesday August 09 2017, @07:56AM (4 children)
With mathematics, you can send out an ever-repeating message that, no matter how long you continue it, within the expected life of the planet, will never be decypherable. Nor will it be detectable that you've changed the payload to something else.
With quantum crypto, becuase an evesdropper is indistinguishable from noise, which is expected, eventually the ever-repeating message will yield enough bits to be decyphered. Similarly, a change to the payload will eventually be detected.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Interesting) by driverless on Wednesday August 09 2017, @09:17AM (3 children)
There's a lot more problems than just those. Since you can't observe the quantum-secured channel (without destroying the data on it), you can't make sure that it's working as required, which is a trivial operation for conventional crypto (pairwise consistency testing of the crypto is a standard requirement for FIPS certification). Another reason it's less safe is that you're now subject to a whole range of implementation glitches and flawed assumptions, some of which have already been noticed over time (see reports at arXiv [arxiv.org] and the IACR ePrint archive [iacr.org]), but many more of which are still to be discovered.
Even if you could overcome all of that, what you end up with is a very short-range version of unauthenticated Diffie-Hellman, circa 1976.
(Score: 2) by tangomargarine on Wednesday August 09 2017, @02:45PM (2 children)
Wouldn't that logic also preclude somebody from eavesdropping on it? Then the original recipient wouldn't receive the right data because it was observed?
I would think "but they could entangle the transmitter" would fall under "access to your hardware means you're fucked" unless you could do *that* long-distance, too.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @09:44PM (1 child)
Partially correct: the original recipient recipient will see bad data if it has been observed - but as the GP mentioned its indistinguishable from noise - so the recipient only knows he is either being observed, or there is noise on the line.
Assuming noise is a normal thing, everyone would always feel like they might be being observed...
(Score: 2) by tangomargarine on Thursday August 10 2017, @02:40PM
Assuming your communications provider is shit...yep, checks out :P
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @04:24AM
I encrypt all of my things with 1492 Qbits, I'm pretty sure I'm safe
(Score: -1, Offtopic) by Anonymous Coward on Wednesday August 09 2017, @06:15AM (2 children)
Help! I lost track of who the bogyman is this week. Are we mad at China now or is it still Russia? I hear North Korea is evil but we're actively fighting in Syria. Some people say immigrants are all rapists and thieves. Arghhh! I can't be scared and obedient if I don't know who the bad guys are.
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @07:01AM
We've always been at war with Eurasia.
(Score: 0) by Anonymous Coward on Wednesday August 09 2017, @09:52AM
You are the bogeyman this week. Be afraid of yourself!