Advance opens door for secure quantum applications without specialized infrastructure
#Hey Kids! Guess which word is getting shoehorned into EVERY technology discussion in 2025 until it becomes meaningless?
Only limited by the speed of light,
What exactly do you think the normal ip data is limited by on the same optical cable?
I thought we were talking about quantum entaglement and spooky action at a distance, which is famously not limited by the speed of light?
Am I missing something obvious?
Yes, quantum entanglement occurs without the speed of light, but we famously cannot interpret information from it faster than the speed of light - it isn’t FTL communication.
famous potatoes
So they’ve shown they can send light over a cable designed to transfer light.
The impressive thing is of course managing to get one specific photon to one specific location. Still, what benefits does that have over the standard encoding?
I guess this technique might have a lower error rate and higher distance, because it’s binary by nature with no quantization needed. But you don’t need the quantum entanglement part at all for this.
Edit: Reading is hard! This is indeed exciting for security. I wonder how it fairs against a very powerful MitM though.
It’s physically impossible to intercept an entangled photon without disrupting the entanglement. The act of observing the photon collapses the quantum uncertainty of it’s state, so even the most sophisticated MitM attempt is going to immediately break the link.
But can you detect the link being broken by someone other than your intended communication partner?
If A sends a particle to B, couldn’t M intercept A’s particle and send a different particle to B? Kind of like intercepting Diffie Hellman. A and B will both share some information with M, but not with each other.
M cannot replicate the particle after they read it, so A and B will detect M’s attempt when they compare results.
The same as classical one-way encryption, it only works through authenticated channel tho. It’s not magic, you have to have some kind of pre-existing secret or rely on third-party authentication
But can you detect the link being broken by someone other than your intended communication partner?
Yes, because breaking the entanglement destroys the link between the photons received at either end.
Observing an entangled photon requires extremely precise timing, the lightspeed lag on the line has to be known down to the nanosecond to ensure that the photon received is paired with the photon at the other end. Even if a MitM wanted to try retransmitting the quantum states it observes on the line, they wouldn’t be able to do so without introducing enough lag to desync the connection.
Alternatively, if M tried sending their own random data in sync with the expected timing, then the bits received by B would only have a 50-50 chance of matching the bits sent from A. Any encryption based on that data would almost immediately begin to suffer a 100% error rate.
The article starts by doing the “quantum” thing that really irks me, where they use confusing terminology to make it sound like “FTL communication” without actually saying it. This is garbage that doesn’t actually matter to the article.
Basically, they found a way to send quantum entangled photons (which exist in a very delicate unobserved state) through existing fiber optic infrastructure without interfering with the standard internet information already travelling through the fiber. A lot of the difficulty with this is due to signal noise that needs to be filtered out. This will be useful communicating quantum measurements over long distances.
It should be a legal requirement to link the actual research paper at the top of science articles
I’ve seen a lot of articles that were like “scientists do this!!” And never link to the actual study (not including this article)
What happened to citing your sources?
2nd paragraph wasn’t good enough, huh?
“Only limited by the speed of light…”
They then go on to describe what sounds like
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transmitting a single specific photon through ‘the internet’, implying start-to-finish with routing (not possible without special infrastructure)
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Use that photon to then send information instantly by manipulating its entangled sibling (also not possible)
So yeah this article is a crock of shit.
The article did not describe either of those things that way. Cynicism is overriding reading comprehension.
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The article starts by doing the “quantum” thing that really irks me
Basically, they found a way to send quantum entangled photons
This is a cool progress forward.
TLDR; Researchers used a 30km optical fiber. They found a wavelength that was off-to-the-side that would mean the quantum entangled photons could ride in the same fiber without interfering (or being interfered with) the classical fiber optic communications. One current shortcoming for scaling this up is that the quantum photons would not survive optical repeaters commonly used for extremely long distant fiber runs. That doesn’t take away from the success of their research, just puts it in perspective for the next researchers to tackle at some point in the future.
Is the reason (Im assuming you ment) it can’t survive a repeater survive a repeater because it collects and recreates the particle? These cables are ment for logical data transport.
Yes. Keep in mind nothing in the article talks about the fiber repeater. That is my addition with some knowledge of telecommunications infrastructure. Because fiber optic cable isn’t perfect, there is light loss over distance. Different grades of fiber have different levels of loss across distance. An example of high end fiber would be ZBLAN. There is experimental level manufacturing (successful in small quantities already) of producing ZBLAN fiber in space to improve the fiber quality, but that makes it much more expensive. Once the limits of the fiber are reached a telecommunications provider can place a fiber repeater to double the length by intercepting the light (signal) and reproducing it (blinking new laser light) into the next segment of fiber.
However, these repeaters create NEW light, and that would mean the quantum information is not carried over in present day fiber repeaters. Even measuring the entangled photon to recreate it would break the quantum state of the entangled photon at the source, so current means can’t be used as a repeater for quantum data.
If I understand it right, this could enable real time connectivity between client and server.
Nope, quantum entanglement can’t enable FTL communication. “Real time” still involves lightspeed lag.
What it does is allows random bits of information to be transmitted in an entangled state. You send an entangled pair of photons, and find out afterwards who got a 1 or a 0 when the photons are observed at either end. They call it ‘quantum teleportation’ because both ends know what the other got, and the information about who got what can’t be intercepted without disrupting the enganglement.
Once they can figure out how to preserve that uncertainty through repeaters, switches, and routers, then we can have a quantum internet that uses encryption based on shared quantum random numbers. It’s likely to be necessary soon since quantum computers might only be a few years from breaking current common encryption techniques.
I also want to clarify, we can create asymmetrical encryption algorithms that are quantum resistant but not quantum themselves
Quantum encryption probably won’t be in mass use anytime soon, but for extra sensitive applications
Thank you for your explanation.
Yup, definitely. Took the words right out of my mouth.
not sure why I read this
Are you not sure because you don’t understand the subject matter or don’t care about it? The first is easy to fix it you’d like. The second would have me just as curious as you are.
the first, I understood nothing but still read it entirely hoping to make some sense of it 😅
This article is building off of the readers assumed knowledge of quantum entanglement. If you don’t have that, they you’d absolutely be lost.
Here’s a simple explanation of quantum entanglement:
Imagine you have four balls of playdoh and a coin. You flip the coin and let in land on the floor. Without looking at which side is up, you smash one of the balls of playdoh over the coin. You gently peal up the playdoh off the coin but are careful to not look at the face of the coin or the impression it left in the playdoh. You take another ball of playdoh and flatten it between your hands. You very gently lay the flattened playdoh over top of the coin-impression playdoh. You pinch just all the edges together. So now you a single piece of playdoh with the coin impression sealed inside. You do the steps of created a second piece of playdoh from the same coin with the same side up (again without looking at it). Lastly, you close your eyes and pick up the coin and put it back in your pocket, again without looking at it. So now you have TWO of these pieces of playdoh with the coin impression sealed inside and you don’t know which coin impression (heads or tails) is in there, but you know its the same one in both. Instead of wrapping the playdoh in plastic so they don’t dry out, you leave them out for a week and they become hard and crusty as playdoh does.
These two pieces of playdoh are essentially what quantum entangled photons are. They contain information (a coin impression of either heads or tails, but not both), both have the SAME information (both will be heads or both will be tails), and there is no way to know if its heads or tails without tearing open the playdoh to look.
Here’s the expanded idea for using quantum entanglement for encryption:
Alice and Bob want to meet each other in secret a week from now. The problem is Bob’s ex girlfriend, Mallory. She’s has been stalking Bob to chase off any potential future girlfriends. To keep Mallory from finding out where they are meeting, you meet both Alice and Bob separately and give them one of the playdoh pieces you created in the first step. They agree that if its “heads” found inside they’ll meet at the restaurant. If its “tails” found inside they’ll meet at the park. If they learn Mallory knows where they’re meeting, they’ll not meet at all. One week later, Alice and Bob each open their playdoh and even though it crumbles, they can both see that the “tails” impression was inside the playdoh. They know each other is going to the park. They successfully meet at the park and Mallory learns nothing of the meeting or who Alice is.
A week later Alice and Bob want to meet again. They take a new pair of playdoh pieces with a new coin impression inside you made for them. This time however, Mallory overheard Bob talking to his friend about this system and what heads and tails mean. Mallory gets into Bobs apartment when he’s out and finds the playdoh. She breaks open the playdoh and sees the “heads” impression and knows it means that the meeting will be at the restaurant. Mallory tries to put the playdoh back together, but its dried and crumbly, so its clear its been opened when she leaves. Bob returns to this apartment and finds the playdoh broken open, also sees the “heads” impression, but knows that someone else knows it too. At the meeting time Alice shows up at the restaurant, as does Mallory looking for Bob and whoever he is trying to meet. Bob doesn’t show. Mallory never learns who Alice is because Bob wasn’t there to meet and identify her there. Alice knows that Mallory is there somewhere because Bob didn’t show and quietly leaves on her own.
So here’s where the article is coming in for using regular internet fiber optics:
Alice and Bob want to meet a third time, and come to you for more playdoh impressions. Instead of each of them coming to your home to pick them up at separate times. You take each piece of playdoh (with the coin impression inside), and put them in cardboard boxes, and drop them in the mail. Alice gets her box and opens it up and finds the playdoh intact. Bob does the same. All of you thought that the playdoh was too fragile to share the same mail system, but the playdoh survived intact with its secret still safe inside!
Why not?
i didnt
