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China Launches World's First Quantum Communications Satellite (theverge.com) 102

hackingbear quotes a report from The Verge: China's quantum network could soon span two continents, thanks to a satellite launched earlier today. Launched at 1:40pm ET, the Quantum Science Satellite is designed to distribute quantum-encrypted keys between relay stations in China and Europe. When working as planned, the result could enable unprecedented levels of security between parties on different continents. China's new satellite would put that same fiber-based quantum communication system to work over the air, utilizing high-speed coherent lasers to connect with base stations on two different continents. The experimental satellite's payload also includes controllers and emitters related to quantum entanglement. The satellite will be the first device of its kind if the quantum equipment works as planned. According to the Wall Street Journal, the project was first proposed to the European Space Agency in 2001 but was unable to gain funding.
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China Launches World's First Quantum Communications Satellite

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  • I'm confused, by QM generally, and this in particular.
    Is there any military application, or are those guys just going to keep using boring old physical key distribution, and one-time-pads for the serious stuff?

    • Re:Any military use? (Score:4, Informative)

      by Z00L00K ( 682162 ) on Tuesday August 16, 2016 @05:17AM (#52710545) Homepage

      The military application is there if the quantum technology is protecting secret communication to a level that makes it impossible for anyone external to view it.

      I wonder if they have been able to also implement a way to detect if someone listens to the signal using entanglement. It would be quite the deal if it was possible to detect that on a wireless signal.

      • Re:Any military use? (Score:5, Interesting)

        by AmiMoJo ( 196126 ) <mojo@w[ ]d3.net ['orl' in gap]> on Tuesday August 16, 2016 @06:55AM (#52710919) Homepage Journal

        This has been proven to work with fibre optic cable. You can't observe a photon without affecting it, and that observation is then detectable. The only difference is that now they are using lasers through the air rather than through fibre optic cables.

        It's not perfect, it's still possible that ways will be found to observe the light in a way that the tamper detection doesn't pick up on, but turning that into something you can reasonably hide in a position to intercept those photons is a not insignificant challenge.

        • by Anonymous Coward

          "It's still possible..."

          You're either referring to side-channel attacks, which exploit imperfections within specific implementations (see "qauntum hacking"), or you believe fundamental theorems of quantum mechanics (specifically the "no cloning theorem") are wrong. The former is legitimate, but not fundamental, and the latter is contrary to all current evidence.

          • by AmiMoJo ( 196126 )

            Yes, side-channel attacks based on weaknesses in the implementation.

            • That's why this satellite won't deliver its promises at my opinion. I doubt it is possible to maintain decent quantum characteristics to perform quantum cryptography in this environment. They will increase the intensity of the laser beam to decrease the error rate which would be otherwise unacceptable. This will open the channel to side attacks.
              • by AmiMoJo ( 196126 )

                We have had optical sensors that can pick up a single photon reflected from a mirror on the moon for decades. While there will certainly be some losses, they are not insurmountable.

        • This has been proven to work with fibre optic cable. You can't observe a photon without affecting it, and that observation is then detectable. The only difference is that now they are using lasers through the air rather than through fibre optic cables.

          It's not perfect, it's still possible that ways will be found to observe the light in a way that the tamper detection doesn't pick up on, but turning that into something you can reasonably hide in a position to intercept those photons is a not insignificant challenge.

          Suppose there were a 100 laser transmitter/receiver pairs on the satellite, set aside for keys. If you use one encrypted message to contain information about which of the 100 lasers would be used to transmit the true key, and when (in milliseconds of time from UTC), I think that there would be a pretty good secure system. One would have to monitor all 100 laser transmitters concurrently, and also know which one sent the message identifying which transmitter will transmit the true key.

          • Suppose there were a 100 laser transmitter/receiver pairs on the satellite, set aside for keys...

            Quantum encryption is not about obscurity. Also, I doubt there would be any transmitter/receiver, but rather it would use reflection. I don't think there would be any receiver/transmitters, as this would break the quantum channel and make reading the initial quantum signal impossible.

            It my understanding that QE is about making sure that only one person/entity can "read" the signal and once the data is read, it cannot be resent in the exact same format. This is good for both sending a one-time-pad for sendin

      • I wonder if they have been able to also implement a way to detect if someone listens to the signal using entanglement. It would be quite the deal if it was possible to detect that on a wireless signal.

        Yes. That is entirely the point of using entanglement.

    • by thesupraman ( 179040 ) on Tuesday August 16, 2016 @06:07AM (#52710723)

      Yes, I would say that secure key distribution has a military application - secure communications.
      Good on them I say, pushing the limits further, real science..

      Compare that with the reaction of the DNC to their hacked emails, by creating a board of lawyers
      and politicos to fix their security problems. I can only assume by pushing for more spying and
      monitoring laws, less encryption, and backdoors in everything, because that helps, right?

      Face it, the Chinese are rapidly become world technology leaders, and denial wont stop it.
      These days it looks like the Chinese are working hard to become the new Renaissance state, while
      the west is rushing to emulate the worst of Maoist stats China through totalitarian control and monitoring
      of their citizens..

      Sad really, but inevitable with a western population that has become too focused on maximising their own
      personal comfort, and running in fear at anything that is unfamiliar or uncomfortable - basically ceding total
      control to a state that is more than happy to grab it and run. Those in power will be laughing all the way
      to the collapse, with little thought to what happens after.

      But dont worry, just keep supporting your liberal left, or your religious right, and ignore the fact that both
      sides are playing the same gave of totalitarian control at any cost, while the east gets on with actual
      production and development.

      • Re: (Score:3, Insightful)

        by invid ( 163714 )
        China's growth has been impressive, and it is a fantastically dynamic country, but it still has significant disadvantages. The portion of its population that is still in poverty exceeds the entire population of the United States, and its government is ramping up its repression of dissent, which is a troubling sign. The transition to a consumer economy will not be easy, and there is still the danger of uprisings. I'm old enough to remember talk of the Soviet Union destroying the American Empire, a united Eur
        • by Applehu Akbar ( 2968043 ) on Tuesday August 16, 2016 @08:46AM (#52711533)

          "The portion of its population that is still in poverty exceeds the entire population of the United States"

          The Chinese cohort of anything exceeds the entire population of the United States. This is also true of the number of Chinese brains being applied to science/tech problems of every kind.

          We fear what our lawyers cannot suppress.

        • The portion of its population that is still in poverty exceeds the entire population of the United States

          Where did you get this? All the sources I can find say that the poverty rate in china is below 15% (actually similar to the US) which is only something like 200 million people.

          Somehow the US is still on top.

          By what metric exactly? All measures of education, poverty, GDP per capita, health outcomes, etc. do not put us in first place. Far from it actually.

          • by invid ( 163714 )

            By what metric exactly? All measures of education, poverty, GDP per capita, health outcomes, etc. do not put us in first place. Far from it actually.

            Raw power.

            • lol okay. Tell me how that matters to anyone that's not a megalomaniac. Does it put food on the table? Help people pay their hospital bills?
              • by invid ( 163714 )

                lol okay. Tell me how that matters to anyone that's not a megalomaniac. Does it put food on the table? Help people pay their hospital bills?

                This is actually an interesting topic. Is it more beneficial for an individual to live in a country with more or less global power? Does global power translate to a better life for a country's citizens? An argument against this is that a global power has to spend resources outside of the country to maintain its power, like for the military, and for financial aid to weaker allies. But there are economic returns for those military expenditures--military dominance does lead to better access to different market

                • military dominance does lead to better access to different markets and resources, whether gotten implicitly or explicitly.

                  I'm just saying, looking at outcomes this is apparently not helping us very much. Our quality of life is substantially lower than countries with little or no military power.

            • "Raw power."

              Not even that.

              Military spending yes - three times as much as China (#2), more than the next 19 combined and more than everything from there down combined.

              The USA has a higher percentage GDP spend on its military than the Soviet Union did at its peak - and it was overspending on the military which finally broke the USSR. That spending is coming at expense of infrastructure (you have bridges and highways rotting), education and healthcare.

              How long until the USA breaks - and who will help keep the

        • I'm old enough to remember talk of the Soviet Union destroying the American Empire,

          I'm old enough (and lived right at the cold war front lines) to remember the USSR came close to it. The USSR lost because it fell for Papa Reagan's Star Wars arms-race trap. The USSR could have continue as-is if it had not attempted to expand. BTW, this should not be construed as an endorsement of the Soviets.

          a united Europe destroying the American Empire,

          I never heard of this one, though the EU is the largest market on the planet. It doesn't need to destroy the US, it simply needs to flourish. Economic dominance is not a zero-sum game.

          OPEC taking over the world,

          They almost did b

      • by gtall ( 79522 )

        "Good on them I say, pushing the limits further, real science..

        Compare that with the reaction of the DNC to their hacked emails, by creating a board of lawyers
        and politicos to fix their security problems."

        Apples and oranges. One is a political-technical set of problems, the other is a purely technical problem. Although your level of thinking might be one reason why the Chinese would supplant the Americans.

        China is anything but a Renaissance state. When they return Tibet to the Tibetans, when they stop their

      • by PPH ( 736903 )

        Good on them I say, pushing the limits further, real science..

        This.

        Meanwhile, our NSA, who should be supporting this sort of R&D, is busy peaking at our porn habits (under right wing administrations) or tracking down our offshore bank accounts (when the left is in power).

      • by Zontar_Thing_From_Ve ( 949321 ) on Tuesday August 16, 2016 @09:34AM (#52712003)
        You do know that China simply steals or buys its way into a lot of technological progress, right? Both the USA and Taiwan have recently arrested people who were happy to pass on secrets of various kinds to their masters in the PRC for money.

        But I also am a bit amused that you seem to think that quantum encryption - if they even pull it off - won't be used for bad purposes for the state. Maybe you're not aware of this, but people in China are not allowed Twitter or Facebook accounts because - I kid you not kid - the government is terrified of their possible use to mobilize the masses against the Communist Party. Mark Zuckerburg can suck up to them all he wants and continue to learn Mandarin in his spare time but it's not going to get them to relax their paranoia against a street revolution.

        I have a question not directed at you. Let's just say for example that they get this to work. Let's say that for now there is no way to break it. Is there a way to mess with the photons so that even if the encryption can't be broken, nobody on either end can use it for communication because it gets scrambled while going between the 2 sites?
        • To answer your question: It's a beam of light. If you put an opaque object in the beam, it will henceforth not work for communication until that object is removed.

          More practically, I would imagine a similar laser aimed at the same receptor, would introduce so many spurious photons that it would be unusable. Similar to radar/radio jamming.

        • You do know that China simply steals or buys its way into a lot of technological progress, right?

          and You do know that the USA simply stole or bought its way into a lot of technological progress too [bloomberg.com], right?

        • "You do know that China simply steals or buys its way into a lot of technological progress"

          Once upon a time the USA achieved its objectives by doing the same thing - and if you don't believe that it's still doing so now, you're somewhat blinkered. ALL countries are doing it, only not so blatently as china (now) or 19th century USA (which was extremely blatent. Ask the Lumiere Brothers how Thomas Edison stole the copyright for _their_ film and sucessfully sued them for exhibiting their own work in New York C

      • The issue that bothers me, is that asymmetrical encryption can utilize multiple keys for decrption, even when the keys are derived from quantum properties, by two parties, who is to know if there isn't a backdoor key thrown in the mix, on the satellite itself?

      • by Anonymous Coward

        ...the Chinese are working hard to become the new Renaissance state, while the west is rushing to emulate the worst of Maoist stats China through totalitarian control and monitoring of their citizens.

        What the actual fuck?! As I write this it is modded +5. This is probably the most bullshit I've ever seen crammed into one senctence and it's at +5. Again, Whisky Tango Foxtrot?!

      • "Face it, the Chinese are rapidly become world technology leaders"

        On put another way, they're resuming their position as world technology leaders. It's only something they lost since the industrial revolution and they didn't lag by much all along.

    • by Anonymous Coward

      Here's a human readable primer on it:
      http://www.techrepublic.com/blog/it-security/how-quantum-cryptography-works-and-by-the-way-its-breakable/

      I've marked the backchannel of extra filtering information with a **** below. You will see this in all Quantum signal experiments. An extra channel of information used to fixup the result. Think about it for a second, you're exchanging KEYS not information, and the KEY exchange itself requires an exchange of a backchannel in a secure way!

      How it works for light:

      Alice u

    • by gweihir ( 88907 )

      Zero applications. This is a stunt. Even if it works (and that is a big "if"), it does not improve anything, but it may be less secure than traditional techniques.

    • Basically, quantum communications like is is a communications channel that reveals when it is being tapped. The accuracy of this detection is very high.

      Hence, I can trivially send you a one-time pad. If you detected a tap, we toss it out, I generate more numbers, and we try again. So, it vastly improves security and key-distribution.

      It gets worse, of course, if I use that one time bad over a quantum encryption channel.

      Now, the channel does have more noise than a standard channel, but that's fixable with

    • I suspect the satellite launch has more of political than military purpose. China's economy is going downhill and so it seems is its hopes of Olympic gold, its standing as number 2 (behind US) being threatened: http://www.reuters.com/article... [reuters.com]

      Who knows, maybe the propaganda bureau decided some good news is in order.

  • by Anonymous Coward

    FTFY.

  • This is for Quantum Key Distribution, right?

    • by AHuxley ( 892839 )
      China knows it is totally surrounded by US, UK listening stations and has been for decades. The NSA, GCHQ used mil and civilian ships, sat, manned and unmanned over flights https://en.wikipedia.org/wiki/... [wikipedia.org], regional bases to try and collect everything. Tai Mo Shan, Little Sai Wan sites could not be hidden...
      China really had a different policy against such expensive and total collection methods. Flood the local gov and mil with random electronic chatter about big projects, massive support needs that mi
  • utilizing high-speed coherent lasers to connect with base stations on two different continents

    -from TFS

    A laser differs from other sources of light in that it emits light coherently.

    - From Wikipedia

    Lasers also operate at the speed of light (albeit the encoding is slower than that). Me wonders what a llow speed incoherent laser looks like? Maybe signal mirrors? What type of technology is China using? /sarcasm

  • It's just me or this seems a load of shit?
  • Laser communication between distant satellites is fraught with difficulties.

    Lasers have a divergence greater than zero. Over huge distances, this results in a very weak signal at the receiving end.

    Lasers exit through an aperture. Diffraction occurs. That spreads the beam, too.

    Lasers have speckle, even if the ends of the chamber (gas or solid state) are polished to be atomically smooth. The lasing cavity, you see, is not one-dimensional, resulting in path-length variation for the lasing photons. So, asi

  • I am more excited to see how the communication using QM entanglement works!

    If it works (per theory), then there would be nearly zero delay, as communication would not be via EM waves (which travel at the slow speed of light).

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