It looked like just another conference call. A panel of suited men sat at a table, large white name tags and water bottles before them. The man in the center, illuminated by fluorescent lights, spoke to a camera in front of him.
[...] The mics, cameras, and screens made for a seemingly ordinary—maybe even boring—meeting-by-telepresence. But behind the scenes, physicists were encrypting the videostream using arguably the most secure technology in existence. Bai and his colleagues were participating on the first-ever intercontinental, quantum-encrypted video conference.
And on Friday, the Chinese and Austrian researchers who engineered the call published how they did it in Physical Review Letters. Led by physicist Jian-Wei Pan of the University of Science and Technology of China, the team relied on networks of optical fiber, a handful of encryption algorithms, and a $100 million satellite that China launched in 2016—the only one specifically designed for quantum cryptography. "They've demonstrated a full infrastructure," says Caleb Christensen, the chief scientist at MagiQ Technologies, which makes quantum cryptography systems that connect a small number of users. "They've connected all the links. Nobody's done that with [quantum encryption] ever."
Story at: Wired
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: 2, Insightful) by Anonymous Coward on Sunday January 21 2018, @09:37PM (2 children)
Meanwhile in the US and Australia, politicians call on the weakening of encryption so the "good guys" can catch the "bad guys".
(Score: 3, Interesting) by MostCynical on Sunday January 21 2018, @09:50PM (1 child)
No, no - they want *strong* encryption..
With backdoors, just for them.
http://webpolicy.org/2015/05/12/we-support-strong-encryption/ [webpolicy.org]
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
(Score: 0) by Anonymous Coward on Monday January 22 2018, @03:24PM
Can they have unicorn ponies as well?
(Score: 4, Interesting) by MostCynical on Sunday January 21 2018, @09:40PM
Apparently, the satellite is able to send and recieve particular types of message.
https://mappingignorance.org/2013/05/06/satellite-based-quantum-cryptography/ [mappingignorance.org]
But, it is possible existing satellites could be used the same way.
https://https://www.sciencedaily.com/releases/2017/06/170615120552.htm.org/2013/05/06/satellite-based-quantum-cryptography/ [https]
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
(Score: 2, Insightful) by Anonymous Coward on Sunday January 21 2018, @09:43PM (2 children)
"At several points in their network, they had to convert quantum information (polarizations) into classical information (voltages and currents) and then back into quantum. This isn’t ideal, because the absolute security of a quantum key relies on its quantum-ness. Anytime the key gets converted into classical information, normal hacking rules apply."
(Score: 2) by c0lo on Sunday January 21 2018, @10:31PM (1 child)
For experimental/demo purposes, this looks good enough for me.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Monday January 22 2018, @08:16AM
A much better demo would have been to have the end point at where now their first repeater was. It would have been the real thing. And we'd have establised a number to beat. (the distance)
Now it's just smoke and mirrors, or magiQ...
(Score: 4, Informative) by legont on Sunday January 21 2018, @09:44PM (7 children)
It was not quantum encryption, but just quantum keys exchange. A very important step indeed, but the announcement is misleading.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 0) by Anonymous Coward on Sunday January 21 2018, @10:33PM (6 children)
And the relevance of this observation is...?
(Score: 1, Interesting) by Anonymous Coward on Monday January 22 2018, @04:27AM (5 children)
It's susceptible to the usual attacks on the encrypted signal. This is just like using a preshared key that's exchanged out of band.
As the GP said, this is an important first step, but quantum encryption could offer far more protection, such as the ability to detect whether somebody else is listening in.
(Score: 2) by maxwell demon on Monday January 22 2018, @08:54AM (4 children)
From the linked article, emphasis by me:
One-time pad encryption is the one classical encryption method that is provably secure. There are no attacks on it. Provably.
The only way to decode OTP-encrypted data is to get hold of the key. And that is what the quantum part is about: secure key sharing.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by tekk on Monday January 22 2018, @02:09PM (3 children)
Of course, the problem with OTP is that the key has to be as long as the message, which makes it impractical for just about anything.
(Score: 0) by Anonymous Coward on Monday January 22 2018, @04:46PM
No, the length of the pad isn't what makes it impractical.
You can break up a message into blocks of whatever size you want and you could apply a new pad for each block.
The impracticality of one time pads lies with the transmission of the pad itself.
How do you transmit the pad to use securely? It has to be encrypted... using some other encryption method.
(Score: 2) by maxwell demon on Monday January 22 2018, @07:33PM (1 child)
That's not a problem if you can non-locally generate the key on the fly. Which is exactly what the quantum part provides.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Tuesday January 23 2018, @09:14PM
Correct, the tricky part is transmitting to the message sender the pad (or if you prefer to call it key) *securely.*
My point was that the length of the pad having to match the length of the message is **not** the fundamental block to everyone using one time pad encryption.
It is the secure transmission of the pad (key) that is the obstacle.
Public key encryption is the worldwide standard because it doesn't have this problem.
(Score: 2) by inertnet on Sunday January 21 2018, @10:29PM (3 children)
Quantum communication is per definition between two endpoints, so a "quantum conference call" is an oxymoron.
(Score: 2) by coolgopher on Sunday January 21 2018, @11:47PM
What about entanglement involving three or more particles?
(Score: 0) by Anonymous Coward on Sunday January 21 2018, @11:51PM
Only if you forget that nearly every network connection is logically and physically point to point.
(Score: 2) by maxwell demon on Monday January 22 2018, @08:57AM
You can have a conference between two places, with several people at each of the two places.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 4, Informative) by leftover on Sunday January 21 2018, @10:40PM (6 children)
It is certainly not quantum encryption, despite the implied claim in the title, and the claim of quantum key exchange is not validated by anything in the abstract. Are they trying to say they accomplished entanglement at an orbital distance? That would be ... bold. What it really seems to me is they had a set of Magic Boxes at routers in a fiber network and these boxes sprinkled Quantum Holy Water onto the transactions at several different places. All actual work is provided by ordinary cryptographic key exchange, which works well.
Making actual advances in cryptography is very hard work, typically by multiple exceptionally bright people. Same for making advances in quantum theory, with even fewer people available who can contribute. The difference between the two is that cryptography has a long history of actual working systems. Not so with quantum systems. Claiming advances in in building actual working quantum systems needs to be accompanied by correspondingly impressive evidence.
Bent, folded, spindled, and mutilated.
(Score: 2) by c0lo on Sunday January 21 2018, @11:19PM (3 children)
Gotta love the S/N-published peer-reviews of scientific papers... they are so in-depth analyzed, so well argued... In addition, many such reviews are based on attempts to reproduce, right?
And it is a known fact of life that neither the Chinese nor the Austrians are capable of 'producing' vary bright people. Dixit!
(grin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Interesting) by leftover on Monday January 22 2018, @12:55AM (2 children)
My point, perhaps very weakly stated, was that the entire Earth has only a few people who can make advances in quantum theory. The current body of theory does not support implementation and the current implementation fits and starts do not inform theory. In this environment, skepticism is the appropriate first response to any claims. Not malice. Not blind acceptance.
Bent, folded, spindled, and mutilated.
(Score: 2) by c0lo on Monday January 22 2018, @01:19AM
Agreed. With both the characterization of your point and the normal expected reaction.
(normal reaction that I think is inclusively applicable to the assertion of "the entire Earth has only a few people who can make advances in quantum theory." - as such, is a "argumentum ad verecundiam" with a lightweight presence for the "authority making the assertion". But I'll admit I don't have enough time to properly check this assertion).
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by GreatAuntAnesthesia on Monday January 22 2018, @03:41PM
Relevant : https://www.youtube.com/watch?v=3wHKBavY_h8 [youtube.com]
(Score: 3, Informative) by maxwell demon on Monday January 22 2018, @08:59AM
https://www.sciencemag.org/news/2017/06/china-s-quantum-satellite-achieves-spooky-action-record-distance [sciencemag.org]
The Tao of math: The numbers you can count are not the real numbers.
(Score: 3, Informative) by pvanhoof on Monday January 22 2018, @10:00AM
A SHA2017 presentation I recently saw that mentions in technical depth what the Chinese are up to can be found here: https://www.youtube.com/watch?v=jHAXme8bPR0 [youtube.com]
(Score: 2) by Wootery on Monday January 22 2018, @11:42AM (1 child)
Rather than communicating as much information as possible, this title is deliberately uninformative. Clickbait. I expect better of SN than to let this fly.
How about First Quantum-Encrypted Videoconference Session Created?
(Score: 3, Funny) by wonkey_monkey on Monday January 22 2018, @04:49PM
It's not clickbait, it's just been written by a newsman from the 1930s:
systemd is Roko's Basilisk
(Score: 0) by Anonymous Coward on Monday January 22 2018, @02:13PM
"the (chine-hehehe) satellite thus establishes a secure key between itself and, say, Xinglong, and another key between itself and, say, Graz.
Then, upon request from the ground command, (the satellite called) Micius (put prunaunced "MyCove)" acts as a trusted relay"
good one, that.