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‘Quantum Internet’ Inches Closer With Advance in Data Teleportation

Summary

Scientists have improved their ability to send quantum information across distant computers — and have taken another step toward the network of the future. Research unveiled this week with a paper published in the science journal 'Nature', demonstrates the power of a phenomenon that Albert Einstein once deemed impossible. Quantum teleportation which can transfer information between locations without actually moving the physical matter that holds it. In the experiment, the network nodes were not that far apart — only about 60 feet. But previous experiments have shown that quantum systems can be entangled over longer distances.

 

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Quotes

Quote

At the Delft University of Technology in the Netherlands, a team of physicists has taken a significant step toward this computer network of the future, using a technique called quantum teleportation to send data across three physical locations.

 

The new experiment indicates that scientists can stretch a quantum network across an increasingly large number of sites. “We are now building small quantum networks in the lab,” said Ronald Hanson, the Delft physicist who oversees the team. “But the idea is to eventually build a quantum internet.”

 

Quantum teleportation not only moves data between quantum computers, but it also does so in such a way that no one can intercept it.

 

Because of decoherence, quantum information cannot simply be copied and sent across a traditional network. Quantum teleportation provides an alternative. Although it cannot move objects from place to place, it can move information by taking advantage of a quantum property called “entanglement”: A change in the state of one quantum system instantaneously affects the state of another, distant one.

 

The team built three of these quantum systems, named Alice, Bob and Charlie, and connected them in a line with strands of optical fiber. The scientists could then entangle these systems by sending individual photons — particles of light — between them. The researchers could then transfer this quantum state to another qubit, a carbon nucleus, inside Bob’s synthetic diamond. Doing so freed up Bob’s electron, and researchers could then entangle it with another electron belonging to Charlie. By performing a specific quantum operation on both of Bob’s qubits — the electron and the carbon nucleus — the researchers could then glue the two entanglements together: Alice plus Bob glued to Bob plus Charlie.

 

The result: Alice was entangled with Charlie, which allowed data to teleport across all three nodes.

 

My thoughts

I think for me the coolest thing about this concept is that with a future quantum internet, it could provide a new type of encryption that at least on paper, is unbreakable. This is because as they explain in the article, the information is not able to be intercepted. They also mentioned in the article that while this experiment the distance wasn't that large, that eventually they will be able to teleport over many miles in several more years. They even claim in the article that they are attempting this right now (outside of the lab). The only downside to this article is they don't necessarily describe the speeds obtained with a quantum internet and if it is faster than something like the fastest available internet today (traditional fiber). Either way, still a good read, and interesting stuff for sure.

 

Sources

https://www.nytimes.com/2022/05/25/technology/quantum-internet-teleportation.html

https://www.nature.com/articles/s41586-022-04697-y

             

 

        

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Quantum is instant, presumably faster than light, because it happens simultaneously on both sides ( I could be wrong) so that will be the peak internet. Hope to live enough to see this.

Btw unbreakable is always a joke. Most of the time the human element is the week point

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1 hour ago, PeachGr said:

Quantum is instant, presumably faster than light, because it happens simultaneously on both sides ( I could be wrong) so that will be the peak internet. Hope to live enough to see this.

Btw unbreakable is always a joke. Most of the time the human element is the week point

There is some subtlety here in that there's a difference between the interaction between the entangled pairs happening instantly and the speed at which information is exchanged. The latter cannot happen at speeds faster than the speed of light, as far as we know. From what I remember from my quantum mechanics courses with entanglement basically the only given is that if something happens at A, then the complementary thing happens at B. You don't have control over what happens, however, and thus exchange of information is not possible. A quick refresher search seems to still support that:

Quote

https://www.nature.com/articles/nature.2012.11163

Because of the link between Alice and Bob forged by entanglement, Bob’s photon instantly feels the effect of the measurement made by Alice. Bob’s photon assumes the quantum state of Alice’s original photon, but in a sort of garbled form. Bob cannot recover the quantum state Alice wanted to teleport until he reverses that garbling by tweaking his photon in a way that depends on the outcome of Alice’s measurement. So he must await word from Alice about how to complete the teleportation — and that word cannot travel faster than the speed of light. That restriction ensures that teleported information obeys the cosmic speed limit.

The news article about this paper mentions that as well (paywalled sadly):

Quote

https://www.nature.com/articles/d41586-022-01364-0

The principle of quantum teleportation is based on the fact that the quantum state of two qubits can be entangled, such that an action (for example, a measurement) on either of the qubits will play out on both qubits, even when they are physically separated. This entanglement acts as a resource for the teleportation process: the sender and receiver share a pair of entangled qubits; the sender then performs a measurement called a Bell-state measurement on the information qubit they wish to teleport and their entangled qubit; and this measurement affects the receiver’s entangled qubit such that a simple operation on it will recover the sender’s information qubit4 (Fig. 1). The only information that is physically sent to the receiver is the operation that is to be performed on the receiver’s qubit. This operation is determined by the random result of the Bell-state measurement, and it carries no information about the teleported quantum state.

You still need to tell the other end how to "decode" your message so to speak, which you will only know once you have sent the message, so no faster-than-light communication yet unfortunately 🙂

 

From reading a bit, what is special about this experiment is that they managed to entangle Alice and Charlie without explicitely doing so. They entangled Alice with Bob and Bob with Charlie while keeping the entanglement between Alice and Bob intact.

 

2 hours ago, BiG StroOnZ said:

The only downside to this article is they don't necessarily describe the speeds obtained with a quantum internet and if it is faster than something like the fastest available internet today (traditional fiber).

This is still a very fundamental experiment (fundamental meaning "can we even do this"  in this context). They make mention of transferring the quantum states at a rate of 1/ (117s), so if you really wanted to put a number on it I guess 0.05 quantum states per second would be it? Still a pretty cool experiment though. Quantum stuff will always have this mysterious air to it.

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2 hours ago, PeachGr said:

Hope to live enough to see this.

we'll probably live long enough to "see" it, not long enough for it to be available to the normal user or cheap enough for the normal user.

🌲🌲🌲

 

 

 

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12 minutes ago, tikker said:

This is still a very fundamental experiment (fundamental meaning "can we even do this"  in this context). They make mention of transferring the quantum states at a rate of 1/ (117s), so if you really wanted to put a number on it I guess 0.05 quantum states per second would be it? Still a pretty cool experiment though. Quantum stuff will always have this mysterious air to it.

 

Yeah, it's definitely rudimentary in that respect. I was still hoping we could get some data rate transfer numbers though (Mbps or MB/s); even if theoretical estimates. Probably a long way off before they could even measure its speed anyway. But Quantum Mechanics has an enigmatical essence (as you say) that makes the experiment a cool read regardless.

 

             

 

        

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2 hours ago, huilun02 said:

Everything sounds better with 'quantum

It's like "millennium" that we ve had at 90s

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Yes so 0.0xxx ping heh.

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It's 2050 and we have quantum phones, quantum internet, quantum cars and Donald trump's grandchild is called Jhonny Quantum Trump.

 

The easiest way to know someone came from the future is summarized In just one word... Quantum. If you're not Quantum you're just a peasant.

 

S*xual attraction is based on your quantum level, not Status or Chinese social credit 

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7 hours ago, BiG StroOnZ said:

 

Yeah, it's definitely rudimentary in that respect. I was still hoping we could get some data rate transfer numbers though (Mbps or MB/s); even if theoretical estimates. Probably a long way off before they could even measure its speed anyway. But Quantum Mechanics has an enigmatical essence (as you say) that makes the experiment a cool read regardless.

 

I'm not sure such a number is possible for this experiment, or in general, as no information is transferred here through entanglement. The quantum state changes instantly, but you still need to tell the other end how to deal with it, making information exchange still limited by existing tech and transfer speeds.

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12 hours ago, PeachGr said:

Quantum is instant, presumably faster than light, because it happens simultaneously on both sides ( I could be wrong) so that will be the peak internet. Hope to live enough to see this.

Btw unbreakable is always a joke. Most of the time the human element is the week point

Good for "over the wire" latency, not necessarily bandwidth. The technology is no good for most use cases if the baud rate is measured with a fractional digit.

If the latency to encode or decode the information is high, that benefit disappears though.

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11 hours ago, tikker said:

There is some subtlety here in that there's a difference between the interaction between the entangled pairs happening instantly and the speed at which information is exchanged. The latter cannot happen at speeds faster than the speed of light, as far as we know. From what I remember from my quantum mechanics courses with entanglement basically the only given is that if something happens at A, then the complementary thing happens at B. You don't have control over what happens, however, and thus exchange of information is not possible. A quick refresher search seems to still support that:

 

Doesn't that imply that a Quantum Calculation will never produce the same answer twice even if you perform the same calculation with the same input values? Not sure how Quantum Computing is supposed to produce useful answers in that case. 

 

In case my line of thinking is non-obvious: If Quantum computers can produce consistent answers to problems then do:

 

Entangle several Quantum Computers with each other, perform X Operations where X is the number of computers on each end.One computer always does the same calculation, (Acting as an "Information is being sent" marker), the others perform one of X-1 possibble calculations, and what order they read out at is your information which can then be decoded.

 

Probably somthing really simple stopping this, (possibly as a simple as you can't entangle complete quantum computers).

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14 minutes ago, CarlBar said:

Doesn't that imply that a Quantum Calculation will never produce the same answer twice even if you perform the same calculation with the same input values? Not sure how Quantum Computing is supposed to produce useful answers in that case. 

In a way, yes. QM is about probabilities. In the Copenhagen interpretation the wave function of a particle, for example, can describe the probability of finding that particle at a certain position and is a superposition of those states. Measuring the position manifests one of those superposition states, after which it will evolve further again. You can't predict where it will appear exactly, because it has a certain probability to appear at any given position that the wavefunction covers.

 

This is now pushing my memories of QM, but entanglement is special and correlates behaviours. When entangled, doing something to A results in something at B that is more than the simple combination (superposition) of A's and B's behaviours. As someone explains here, though, because of the probabilistic nature of a measurement you need to know both outcomes to figure out whether the thing you measure at B is because the other end did something, or because you simply got that measurement. I found this explanation reasonably clear: https://physics.stackexchange.com/questions/512504/in-layman-terms-why-cant-quantum-entanglement-be-used-to-achieve-ftl-communica

 

It is important for transferring quantum information as the article in the OP mentions.

38 minutes ago, CarlBar said:

Entangle several Quantum Computers with each other, perform X Operations where X is the number of computers on each end.One computer always does the same calculation, (Acting as an "Information is being sent" marker), the others perform one of X-1 possibble calculations, and what order they read out at is your information which can then be decoded.

 

Probably somthing really simple stopping this, (possibly as a simple as you can't entangle complete quantum computers).

I am not sure I understand your thought experiment. How would the order they read out be information and what information would that be? I also don't know how entanglement of a macroscopic system would work, if that even works. Quantum computers won't yet or ever be this magical weapon making everything else futile due to all its intricacies. It can and does absolutely suck for (most) classical tasks.

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15 hours ago, BiG StroOnZ said:

This is because as they explain in the article, the information is not able to be intercepted.

This is only in the most simplistic sense. Sure, you can't intercept it by physically tapping a wire (which isn't really how any modern networking attack works), but any large scale network using this would route your packages through dozens of gateways and devices that would handle and therefore be able to intercept and access your packages.

 

Just consider the example of the experiment - what if Bob connected Alice to Duncan instead of Charlie? Would Alice be able to tell?

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12 hours ago, tikker said:

I'm not sure such a number is possible for this experiment, or in general, as no information is transferred here through entanglement. The quantum state changes instantly, but you still need to tell the other end how to deal with it, making information exchange still limited by existing tech and transfer speeds.

 

I figured that much, at least for what we are capable of doing currently. But it does say that the end result of the experiment results in data being transferred. Perhaps at the end of the sequence, the measurement could be implemented then and that's where you would get information exchange making such a number possible.

 

6 hours ago, Sauron said:

This is only in the most simplistic sense. Sure, you can't intercept it by physically tapping a wire (which isn't really how any modern networking attack works), but any large scale network using this would route your packages through dozens of gateways and devices that would handle and therefore be able to intercept and access your packages.

 

Just consider the example of the experiment - what if Bob connected Alice to Duncan instead of Charlie? Would Alice be able to tell?

 

I do see what you're saying, however, a question I do have is would the "quantum encryption" still be better than what we have available today? If the answer is yes, then I guess the technology is still beneficial despite data being able to be intercepted on some level. 

 

             

 

        

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15 hours ago, tikker said:

I am not sure I understand your thought experiment. How would the order they read out be information and what information would that be? I also don't know how entanglement of a macroscopic system would work, if that even works. Quantum computers won't yet or ever be this magical weapon making everything else futile due to all its intricacies. It can and does absolutely suck for (most) classical tasks.

 

Not sure what part your not getting so going to go real basic. Also where i need to use a example calculation i'm going to stick to simple classical addition. i know thats not what Quantum computers are good at, but i don't know enough to devise an actual quantum computing calculation example. Simply substitute the classical example for an actual Quantum Computer capable workload.

 

The point of the collection of quantum computers isn't to do work. Your running calculations on them as a means of transmitting the information.

 

Lets tackle an example of 5 computers. A, B, C, D, and E.

 

A does the sum 2+2 over and over, the transmitting entity sets up the calculation, let it run for a preset time period, then reset it. The receiving party measures the output, (just as someone running the computer to do work would), at set intervals, since the receiving station knows the calculation being run is 2+2 and that the output of that is 4. So if when they measure they get a result of 4 they know information is being transmitted.

 

The other 4 computers, (B, C, D, and E), do not run a fixed calculation, instead there are four other calculations, (Let us say 3+3, 4+4, 5+5, and 6+6). Each time computer A is reset to run it's calculation, you run a calculation on each of these other computers. Each one gets a different calculation, but which computer gets which calculation depends on the information content on the message. As an example one possible state Computer B has 6+6, Computer, C has 5+5, Computer D has 4+4, and Computer E has 3+3. An alternate state would be the obvious; Computer B has 3+3, Computer C has 4+4, Computer D has 5+5, and Computer E has 6+6.

 

Since all 6 computers are allways starting and stopping at the same time and Computer A  allways runs the same calculation regardless of the data transmitted you have a method of knowing when data is being transmitted, and a way, (through the known outputs of the sums being run on the other computers), of confirming that your getting a usable output out of the other 5 computers.

 

Technically your not even getting around the requirement for the transmission of information by a conventional method, it's just that said information is a single time data-set, (the sums being run and the cycle time), that only has to be sent once, rather than a continuous signal.

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3 hours ago, CarlBar said:

The point of the collection of quantum computers isn't to do work. Your running calculations on them as a means of transmitting the information.

I think running calculations and transmitting the information would count as doing work. If not, what do you define as doing work in this context?

3 hours ago, CarlBar said:

Lets tackle an example of 5 computers. A, B, C, D, and E.

 

A does the sum 2+2 over and over, the transmitting entity sets up the calculation, let it run for a preset time period, then reset it. The receiving party measures the output, (just as someone running the computer to do work would), at set intervals, since the receiving station knows the calculation being run is 2+2 and that the output of that is 4. So if when they measure they get a result of 4 they know information is being transmitted.

The receiving party cannot measure the outcome at the location of the sending party, because they don't have that quantum system at their location. They can only measure what happens locally on their end. The sender can measure something on their end and the receiver can measure something on their end. They then need to put both measurements together to figure out what happened due to what.

3 hours ago, CarlBar said:

The other 4 computers, (B, C, D, and E), do not run a fixed calculation, instead there are four other calculations, (Let us say 3+3, 4+4, 5+5, and 6+6). Each time computer A is reset to run it's calculation, you run a calculation on each of these other computers. Each one gets a different calculation, but which computer gets which calculation depends on the information content on the message. As an example one possible state Computer B has 6+6, Computer, C has 5+5, Computer D has 4+4, and Computer E has 3+3. An alternate state would be the obvious; Computer B has 3+3, Computer C has 4+4, Computer D has 5+5, and Computer E has 6+6.

Assuming macro-scale entanglement is possible and that it works the same as for particles, if A, B, C, D and E are entangled, then you get a system l ike "if I find A doing this, B, C, D and E are probably this". Forcing A into a particular state, however, (e.g. forcing it to give the answer '4') would break the entanglement of at least A with the rest since you're no longer simply measuring 4 as the outcome, but changing the entiresystem such that 4 is the outcome at A.

3 hours ago, CarlBar said:

Since all 6 computers are allways starting and stopping at the same time and Computer A  allways runs the same calculation regardless of the data transmitted you have a method of knowing when data is being transmitted, and a way, (through the known outputs of the sums being run on the other computers), of confirming that your getting a usable output out of the other 5 computers.

But you wouldn't know whether you measuring computer C to be doing 5+5 is a result of particular data being transmitted at A or simply a realisation of the state of the entangled system. To confirm that you would still have to communicate with the sending side via other means to find out what happened at A to then correlate that with what happened at C.

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40 minutes ago, tikker said:

I think running calculations and transmitting the information would count as doing work. If not, what do you define as doing work in this context?

The receiving party cannot measure the outcome at the location of the sending party, because they don't have that quantum system at their location. They can only measure what happens locally on their end. The sender can measure something on their end and the receiver can measure something on their end. They then need to put both measurements together to figure out what happened due to what.

Assuming macro-scale entanglement is possible and that it works the same as for particles, if A, B, C, D and E are entangled, then you get a system l ike "if I find A doing this, B, C, D and E are probably this". Forcing A into a particular state, however, (e.g. forcing it to give the answer '4') would break the entanglement of at least A with the rest since you're no longer simply measuring 4 as the outcome, but changing the entiresystem such that 4 is the outcome at A.

But you wouldn't know whether you measuring computer C to be doing 5+5 is a result of particular data being transmitted at A or simply a realisation of the state of the entangled system. To confirm that you would still have to communicate with the sending side via other means to find out what happened at A to then correlate that with what happened at C.

 

I get where the confusion is coming from. I'm saying The sender and receiver each have 6 Quantum Computers and you have the Qubits that make up Computer A on the sender end entangled with the QBits that make up Computer A on the receiver end. So when you input a problem into Computer A on the sender end, your also imputing it into Computer A on the receiver end. Ditto for Computers B, C, D, and E.

 

And if the receiver knows what the problem/s being inputted are, and what the answer to that problem should be, they can use the output on their end to find out what the problem being input is if the rnage of possibble inputs is adequately restricted.

 

That said it sounds like your saying in the third paragraph you can't input a problem on one end without breaking the entanglement. Which has me scratching my head a bit about how entangled communication with the light-speed side channel is supposed to work, if you can't manipulate the state of the entangled particle on the sender end how can information be encoded on it for the receiver to decode with the help of the side channel.

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13 hours ago, BiG StroOnZ said:

I do see what you're saying, however, a question I do have is would the "quantum encryption" still be better than what we have available today? If the answer is yes, then I guess the technology is still beneficial despite data being able to be intercepted on some level. 

As far as I understand it, this and the concept of "quantum encryption" (by which I assume you mean quantum key exchange) are separate and don't strictly require each other to work. We also have key exchange techniques that work on regular networks and are basically invulnerable to attack from anything we have or could even conceive of having in the next few decades - it's a matter of adoption rather than ability.

 

To be clear, if this could be made to work well on compact and stable hardware that doesn't stop working if moved it would definitely have its uses, for instance you could entangle a device on a plane or a rocket and use it to communicate when direct connections are difficult or impossible. Plus latency could be very low after the systems have been entangled... but I don't know if any of this is actually possible. I'm just saying that the technology as presented doesn't really add anything to the privacy of a regular internet user on its own.

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2 hours ago, CarlBar said:

 

I get where the confusion is coming from. I'm saying The sender and receiver each have 6 Quantum Computers and you have the Qubits that make up Computer A on the sender end entangled with the QBits that make up Computer A on the receiver end. So when you input a problem into Computer A on the sender end, your also imputing it into Computer A on the receiver end. Ditto for Computers B, C, D, and E.

Once they're entangled they are no longer independent or in normal superposition. You get a new state with X% chance of measuring A_receiver in some state if A_sender is in some state or v.v. I think putting them both in the same state would break the entanglement as that is not the entangled state. I also have a feeling that this violates the idea that there are no 'hidden variables', that is there are no (unknown) underlying things that completely describe the states of the particles that would allow us to predict outcomes if we knew those variables.

Quote

https://physics.stackexchange.com/questions/3158/why-is-quantum-entanglement-considered-to-be-an-active-link-between-particles
An important fact in this reasoning is that the results of the correlated measurements are still random - we can't force the other particle to be measured "up" or "down" (and transmit information in this way) because we don't have this control even over our own particle (not even in principle: there are no hidden variables, the outcome is genuinely random according to the QM-predicted probabilities).

 

2 hours ago, CarlBar said:

And if the receiver knows what the problem/s being inputted are, and what the answer to that problem should be, they can use the output on their end to find out what the problem being input is if the rnage of possibble inputs is adequately restricted.

Entanglement doesn't work in an 'if A_sender finds 4 then A_receiver also finds 4' way. The entangled state correlates the behaviour of the two and gives you a probability that if A_sender measures 4 that A_receiver also measures 4, but knowing the inputs is not enough as your measurements will still be random. We still end up at the point that if the receiver measures 4 that they need to know what the sender measured in order to know if what they measured was simply a realisation of the entangled state, or a consequence of A_sender doing something specific.

 

Incidentally while reading up on this I found a video about attempting 1+2 on a quantum computer:

You can see the probabilistic nature of QM pop up in that the quantum system will tell you that there's a 78% chance of finding it in the '11 state' (binary numbers) , or, loosely speaking that it determined a "78% chance" of 1+2 being 3. (and as he says it makes no sense to do this with quantum computers ;))

2 hours ago, CarlBar said:

That said it sounds like your saying in the third paragraph you can't input a problem on one end without breaking the entanglement. Which has me scratching my head a bit about how entangled communication with the light-speed side channel is supposed to work, if you can't manipulate the state of the entangled particle on the sender end how can information be encoded on it for the receiver to decode with the help of the side channel.

This is why entanglement itself can't be used for communication. The information that you are after is contained in observing a change in the correlation of the systems, for example. I think the earlier SE answer is more or less what you are attempting in your thought experiment:

Quote

One sets up a stream of entangled arrow-pairs, going to Alice and Bob. Let's say they both observe the arrows in the north-south direction (using the pole star Polaris to indicate north), and thus get perfectly correlated results. Then one day Alice, who lives near Alpha Centauri, wants to tell Bob, on Earth, that her answer is "yes".
<snip>
So she switches her apparatus. What is the effect at Bob? There is no effect at all: all his observed outcomes continue to be random, just as they were before. But meanwhile Alice decides to send to him her observed outcomes, which she can do by light-speed-limited "snail mail". Four years after Alice switched her apparatus, Bob starts to notice that their two observation streams stopped being correlated at a moment 4 years ago. Thus he receives the information communicated by Alice, but he can only receive it by observing the change in the correlation, not by any change in the data at his end alone.

 

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@tikker Ok think i get it, question though, doesn't that mean the moment Alice makes a change on her end, her and Bob's systems stop being entangled?

 

The way Entanglement allways gets explained to me is that both Alice and Bobs arrows are spinning super fast between north and south, (and at random when they switch),  but if you where somehow able to use a high speed camera to capture both ends at the same time you'd see them pointing the same way. So when Alice briefly, (too short a time span to see visually but still happening), stops hers facing one way it influences the odds of all future north-south measurements, creating a change in the probability distribution of future measurement which with the side-band Bob can see since he can isolate his data-set of measurements to start from the instant she stopped her end facing a specific direction to see the change in probability distribution resulting from that stoppage.

 

What you seem to be saying however is that after Alice briefly stops her arrow then bob's arrow no longer matches hers and it's that lack of matching probability distribution that conveys the information?

 

 

Also thanks for being willing to go through this with me. QM is one of those things i find fascinating but at the same time have a lot of trouble understanding.

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7 minutes ago, CarlBar said:

@tikker Ok think i get it, question though, doesn't that mean the moment Alice makes a change on her end, her and Bob's systems stop being entangled?

 

The way Entanglement allways gets explained to me is that both Alice and Bobs arrows are spinning super fast between north and south, (and at random when they switch),  but if you where somehow able to use a high speed camera to capture both ends at the same time you'd see them pointing the same way. So when Alice briefly, (too short a time span to see visually but still happening), stops hers facing one way it influences the odds of all future north-south measurements, creating a change in the probability distribution of future measurement which with the side-band Bob can see since he can isolate his data-set of measurements to start from the instant she stopped her end facing a specific direction to see the change in probability distribution resulting from that stoppage.

 

What you seem to be saying however is that after Alice briefly stops her arrow then bob's arrow no longer matches hers and it's that lack of matching probability distribution that conveys the information?

 

 

Also thanks for being willing to go through this with me. QM is one of those things i find fascinating but at the same time have a lot of trouble understanding.

QM is one of the weirdest things we've created, but it works, so we have to deal with it 😛 Yes, making a change will affect the entanglement. While entangled, if Alice measures her arrow to point up Bob's arrow will point somewhere, e.g. up. Both Alice and Bob's measurements will be based on the probabilities of the entangled state. If Alice makes it point up, or left, or any direction then Bob will at some point notice that his measurements no longer correlate with Alice's. Bob's arrow isn't just switching from up to down. It has the same randomness as Alice's measurements, so thing to figure out is whether Alice's change did or didn't cause Bob's outcome. That is something they can only know after communicating about both their outcomes, since you need both outcomes to deduce they no longer correlate.

Crystal: CPU: i7 7700K | Motherboard: Asus ROG Strix Z270F | RAM: GSkill 16 GB@3200MHz | GPU: Nvidia GTX 1080 Ti FE | Case: Corsair Crystal 570X (black) | PSU: EVGA Supernova G2 1000W | Monitor: Asus VG248QE 24"

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9 hours ago, Sauron said:

As far as I understand it, this and the concept of "quantum encryption" (by which I assume you mean quantum key exchange) are separate and don't strictly require each other to work. We also have key exchange techniques that work on regular networks and are basically invulnerable to attack from anything we have or could even conceive of having in the next few decades - it's a matter of adoption rather than ability.

 

To be clear, if this could be made to work well on compact and stable hardware that doesn't stop working if moved it would definitely have its uses, for instance you could entangle a device on a plane or a rocket and use it to communicate when direct connections are difficult or impossible. Plus latency could be very low after the systems have been entangled... but I don't know if any of this is actually possible. I'm just saying that the technology as presented doesn't really add anything to the privacy of a regular internet user on its own.

 

From my understanding of this experiment, the information being transferred is in qubits. So I'm guessing quantum key exchange would apply automatically. I never heard of SIDH (Supersingular isogeny key exchange), that was a cool read, thanks for that. But that is definitely a matter of adoption, but the question is what is preventing its adoption of course. There were a few papers about ARM powered platforms trying to implement the technology. Which possibly means we could see the technology on cellphones first.

 

If what you're saying is correct (that the tech doesn't provide anything better privacy wise than what is already available). I'm wondering why in the article they tried to glorify the ability of the information not being able to be intercepted, because the encryption being unbreakable from the quantum teleportation method?

             

 

        

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1 minute ago, BiG StroOnZ said:

From my understanding of this experiment, the information being transferred is in qubits. So I'm guessing quantum key exchange would apply automatically.

Not really, a quantum key exchange is used to share a normal encryption key. If the data for an encryption key is shared through quantum means then it is quantum key sharing - that doesn't mean that's what you're doing every time you use a qubit, not does it mean the information you're transmitting is automatically encrypted.

3 minutes ago, BiG StroOnZ said:

But that is definitely a matter of adoption, but the question is what is preventing its adoption of course.

Usually it's just backwards compatibility. If everyone uses RSA it's hard to get them to switch to something else as soon as it's available, especially considering RSA is still pretty damn good. Sometimes it's also a matter of performance - you could use some insanely long RSA keys, which would improve security, but then traffic decryption speed would take a hit.

6 minutes ago, BiG StroOnZ said:

If what you're saying is correct (that the tech doesn't provide anything better privacy wise than what is already available). I'm wondering why in the article they tried to glorify the ability of the information not being able to be intercepted, because the encryption being unbreakable from the quantum teleportation method?

What they're saying in the article is that theoretically since the information is teleported directly to the recipient there's no opportunity for an attacker to intercept and read it, even if it's unencrypted - with the other end of the spectrum being open wifi where you can literally just read what packets people are sending using only a wifi dongle and wireshark (though of course if the packets themselves are encrypted through TLS that's not necessarily a problem).

 

As I mentioned however that's some pretty flawed reasoning, at least when applied to a realistic network made with this tech; while wireless sniffing may not be possible it would still be perfectly possible to set up a malicious gateway for a man-in-the-middle attack. Sometimes tech journalists end up speculating a bit too much about things they don't necessarily understand... and sometimes researchers are a bit too optimistic about their results because that gets them funding.

Don't ask to ask, just ask... please 🤨

sudo chmod -R 000 /*

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