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All-Photonic Quantum Repeaters Could Lead To a Faster, More Secure Global Quantum Internet (phys.org)
"University of Toronto Engineering professor Hoi-Kwong Lo and his collaborators have developed a prototype for a key element for all-photonic quantum repeaters, a critical step in long-distance quantum communication," reports Phys.Org. This proof-of-principle device could serve as the backbone of a future quantum internet. From the report: In light of [the security issues with today's internet], researchers have proposed other ways of transmitting data that would leverage key features of quantum physics to provide virtually unbreakable encryption. One of the most promising technologies involves a technique known as quantum key distribution (QKD). QKD exploits the fact that the simple act of sensing or measuring the state of a quantum system disturbs that system. Because of this, any third-party eavesdropping would leave behind a clearly detectable trace, and the communication can be aborted before any sensitive information is lost. Until now, this type of quantum security has been demonstrated in small-scale systems. Lo and his team are among a group of researchers around the world who are laying the groundwork for a future quantum Internet by working to address some of the challenges in transmitting quantum information over great distances, using optical fiber communication.
Because light signals lose potency as they travel long distances through fiber-optic cables, devices called repeaters are inserted at regular intervals along the line. These repeaters boost and amplify the signals to help transmit the information along the line. But quantum information is different, and existing repeaters for quantum information are highly problematic. They require storage of the quantum state at the repeater sites, making the repeaters much more error prone, difficult to build, and very expensive because they often operate at cryogenic temperatures. Lo and his team have proposed a different approach. They are working on the development of the next generation of repeaters, called all-photonic quantum repeaters, that would eliminate or reduce many of the shortcomings of standard quantum repeaters. "We have developed all-photonic repeaters that allow time-reversed adaptive Bell measurement," says Lo. "Because these repeaters are all-optical, they offer advantages that traditional -- quantum-memory-based matter -- repeaters do not. For example, this method could work at room temperature."
Because light signals lose potency as they travel long distances through fiber-optic cables, devices called repeaters are inserted at regular intervals along the line. These repeaters boost and amplify the signals to help transmit the information along the line. But quantum information is different, and existing repeaters for quantum information are highly problematic. They require storage of the quantum state at the repeater sites, making the repeaters much more error prone, difficult to build, and very expensive because they often operate at cryogenic temperatures. Lo and his team have proposed a different approach. They are working on the development of the next generation of repeaters, called all-photonic quantum repeaters, that would eliminate or reduce many of the shortcomings of standard quantum repeaters. "We have developed all-photonic repeaters that allow time-reversed adaptive Bell measurement," says Lo. "Because these repeaters are all-optical, they offer advantages that traditional -- quantum-memory-based matter -- repeaters do not. For example, this method could work at room temperature."
in 100 years when it works
You can't trust the data as soon as it leaves your computer. If it hasn't been encrypted by that point, it doesn't really matter if AT&T encrypts their transmission lines.
"First they came for the slanderers and i said nothing."
YEEAAHHH!!!111one
it's like yelling.
You don't have a working product over short distances to sell, because it has a "successful entanglement" signal. That signal is used to pre-filter the result.
You don't have "time-reversed" anything, because the filter signal runs forward in time only.
You don't even have properties that are independent, let alone set across space and time when you measure one of the 'entangled" photons.
******
Light's properties all stem from either directly from its oscillation, or indirectly from its oscillation interacting with the matter around it. These properties are *not* independent.
You *know* already it has an electric/magnetic oscillation, you've already observed that. It's accepted science.
You *know* already, it interacts with matter, e.g. you pass it through slits in a polarizing grate and it spreads out. YOU USE THESE EFFECTS TO MEASURE THE PROPERTIES INDIRECTLY.
So the only thing that's saying its properties are all independant and all carried with "a photon", is your theory.
The observation says they're connected always, not just via 'entanglement/teleportation' but via matter, the very mechanisms you use to measure these properties.
1) To have a property that is independent of the oscillation, there would have to be no connection between those properties.
You know light bends differently based on wavelength as it interacts with matter i.e. the oscillation interacts with matter and this is observed and known.
2) And you *measure* other properties by interacting with matter (e.g. sending it through a polarizing grating etc.), again a proof that these properties are ALSO connected via the interaction with matter, already observed and known.
3) So these properties all have an easily demonstratable linkage through interacting with matter. You yourselves measure these properties using that interaction in your experiment!
4) So they are not independent, so their connection is not through "entanglement", so your Entanglement theory is false.
These properties do not "teleport" from one photon to another when you try to measure them. Either they repeat due to an oscillation, or they are properties added by interaction with that oscillation.
Man up, recognize the false nature of this model, and strike it down as proved false. It's false. The premise is false, the experiments show it as false, any equation that requires it is also false. You do not have even the faintest explanation for the "quantum teleportation" mechanism, beyond "it must be true because my theory needs it".
Article seems like nonsense to me. We already have secure transmission by end-to-end encryption.
Securing the transmission channel further will do nothing to enhance that, and nothing to stop the hacking mentioned in the article.
What possible use is quantum key distribution?
If you can authenticate, you already have secure key distribution, and if not, you are still vulnerable to man-in-the-middle, no?
Governments and Internet Ad companies hate this because they won't be able to listen into our traffic. So this technology will not be available for us plebs.
Heroes die once, cowards live longer.
With my server, I did the following:
Client and server have a hard disk full of high-quality random data.
ALL packet data is XORed with that random data, incoming and outgoing.
Used random data is overwritten with zeroes and marked as used immediately.
I'm being told, XOR encryption is "mathematically proven" to be "perfect".
Of course, once you know about the Intel Management Engine, hacked firmware, and even dopant-level hardware backdoors ... or just somebody breaking into your building and/or using a $3 wrench, you realize that *if* you need *that* level of protection, even *perfect* encryption won't help you.
Faster porn!
The problem with internet security is 100% developer responsibility. Lack of investment on security and no update plans for almost every IoT device are the main problems
How is quantum logic going to prevent bad, outdated code?
Just asking for a friend, ..?
Pick up a book of optical illusions for more quatum revelations. Observation is over-rated... your eyeballs are poor sensors and time is all in your head.
For thousands of years, coders have promised "to provide virtually unbreakable encryption". Hackers cracked all of them, usually quite quickly. I'll wager quantum encryption will fare no better.
âoeThese repeaters boost and amplify the signalsâoe
Whats the difference between boost and amplify?
They boost and amplify and enlarge and reinforce and swell and grow and increase and embiggen the signals.
the biggest security risks are due to how top level routers determine where IPv4 addresses route. If someone claims more of the address, e.g. /4, they get all the traffic. It is a total HONOR system. Fix routing first.
if your quantum signal has multiple photons and you can afford to lose some of them (attenuation) then it can't be secure since I can pick off some of your photons and measure them.
If you can amplify your quantum encoded signal, and that increases the number of photons without destroying the entanglement, then again I can pick off some of these.
I suppose that one might be viewing this probablistically. e.g. there's only one photon and the repeater only out puts one photon. All that might be changing is the probability that the photon goes further before it is attenuated. But you are not changing the number of photons. However it's hard to see how that could be done.
Quantum theory is the best theory we have to explain many experimental results, e.g. why light "behaves like particles" (i.e. photoelectric effect) or electrons show diffraction effects you'd expect from waves. QT is used successfully to model all kinds of physics, e.g. properties of atoms, or even strange properties of the vacuum like the Casimir effect, and in that sense QT is a working product. It was noticed early on (EPR-"paradoxon"), that QT predicts some strange things including what we call "entanglement". The strangeness lies in the nonlocality that it implies for QT, which is at odds with a "classical" (in the sense of non-QT) world view and manifests itself in "entanglement" i.e. some strange "connection" between particles in different locations. But the strange behavior predicted by QT was tested, specifically by testing the Bell-inequality. The result of these tests is not only, that the strange predictions of QT are indeed what we measure experimentally, but also that it will be impossible to explain these results with a "classic" theory that is based on locality and causality, even any (finite) number of "hidden" variables don't help. Another test of entanglement are "Delayed Choice Quantum Eraser" experiments which also confirm the strange predictions of QT.
QT is far from perfect, as it doesn't go well together with general relativity, but for nonrelativistic phenomena on the scale where quantum effects are of relevance it's the best we have. It can also be shown how "classical" Newtonian physics emerges for large (many particle) objects from QT.
Some people think that QT must be wrong because it clashes with their "classical" picture of the world, a picture humans grow accustoms to since their life usually doesn't confront them with phenomena on the scale of single atoms, electrons and photons, but why should the universe conform to our personal world view or preferences?
But anyone claiming that QT is wrong (apart from known limitations i.e. incompatibility with GR) should point out where it makes wrong predictions, and anyone presenting a "better" theory should make that theory specific and detailed enough so it can be tested experimentally, and of course that theory should also explain all that experimental findings that are perfectly well explained by QT. As it stands QT is the best explanation of all the stuff we find experimentally, but also the nature of atoms as we know them.
Specific to light we have QED (quantum electrodynamics), see also the book "QED: the strange theory of light and matter" by R:P: Feynman:
https://en.wikipedia.org/wiki/...
The point is: While we can't ultimately prove of any physical theory if it is "correct" under all circumstances (because we don't know and can't monitor all circumstances), we can test if the predictions of a theory match experimental results and is consistent with what we "know" about the world (i.e. all those other theories, observations etc.). In that sense QT is the best theory we currently have, and we do know that classical theories that preserve "locality" and "causality" are in contradiction with at least some experimental findings (e.g. bell inequality tests).
"By the way if anyone here is in advertising or marketing... kill yourself." -- Bill Hicks
This is some world-class technobabble..
Wonder if quantum internal introduces new vulnerabilities. For example, observe the transmission and you've broken the communication. Not to mention, we don't really understand quantum physics ... next year's discovery could invalidate a generation of technology.
Quantum key distribution (QKD). QKD exploits the fact that the simple act of sensing or measuring the state of a quantum system disturbs that system. Because of this, any third-party eavesdropping would leave behind a clearly detectable trace, and the communication can be aborted before any sensitive information is lost. Until now, this type of quantum security has been demonstrated in small-scale systems.
Existing repeaters for quantum information are highly problematic. They require storage of the quantum state at the repeater sites, making the repeaters much more error prone, difficult to build, and very expensive because they often operate at cryogenic temperatures.
Commander Data continued, "Using the deflection dish, though, it should scale up enough to allow us to detect the warp anomaly and free the USS Maelstrom."
(-1: Post disagrees with my already-settled worldview) is not a valid mod option.
If quantum key exchange is secure, then quantum repeaters won't work. If quantum repeaters work, then quantum key exchange is not secure.
It isn't possible to have both. Of the two it appears that the repeaters don't work.