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Creating the First Quantum Internet (axios.com)
Scientists in Chicago are trying to create the embryo of the first quantum internet. If they succeed, the researchers will produce one, 30-mile piece of a far more secure communications system with the power of fast quantum computing. From a report: The key was the realization of an unused, 30-mile-long fiber optic link connecting three Chicago-area research institutions -- Argonne National Lab, Fermi Lab and the University of Chicago. This led to the idea to combine efforts and use the link for what they call the Chicago Quantum Exchange.
David Awschalom, an Argonne scientist and University of Chicago professor who is the project's principal investigator, tells Axios that the concept is difficult to grasp, even for experts. MIT Technology Review elaborates: The QKD approach used by Quantum Xchange works by sending an encoded message in classical bits while the keys to decode it are sent in the form of quantum bits, or qubits. These are typically photons, which travel easily along fiber-optic cables. The beauty of this approach is that any attempt to snoop on a qubit immediately destroys its delicate quantum state, wiping out the information it carries and leaving a telltale sign of an intrusion. The initial leg of the network, linking New York City to New Jersey, will allow banks and other businesses to ship information between offices in Manhattan and data centers and other locations outside the city.
However, sending quantum keys over long distances requires "trusted nodes," which are similar to repeaters that boost signals in a standard data cable. Quantum Xchange says it will have 13 of these along its full network. At nodes, keys are decrypted into classical bits and then returned to a quantum state for onward transmission. In theory, a hacker could steal them while they are briefly vulnerable.
However, sending quantum keys over long distances requires "trusted nodes," which are similar to repeaters that boost signals in a standard data cable. Quantum Xchange says it will have 13 of these along its full network. At nodes, keys are decrypted into classical bits and then returned to a quantum state for onward transmission. In theory, a hacker could steal them while they are briefly vulnerable.
In theory, a hacker could steal them while they are briefly vulnerable.
In practice, some three-letter agency or foreign power will steal them.
FTFY
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The problem is the fleshy creatures on either side of the communications line. Alas that meat bad will likely be the weak point.
The compromised shitboxes that exist today?
Far more secure : No
More security margin against specific attacks : Yes.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
Chicago Quantum Exchange
Great. So traders will know where the market is going or where it is, but not both.
I imagine Heisenberg wouldn't like uncertainty when it comes to his principle - or dividends ...
It must have been something you assimilated. . . .
I got excited for a second hoping it would be 0 latency quantum-entangled internet.
So these repeaters are trusted.. how? It doesn't sound any more secure since the encryption is broken 13 times over 30 miles... sounds more like a game of telephone to me.
A nice 8193 bit key should be as much protection as anyone ever needs.
While Bill Gates never said that it may be true for as long as necessary. Just use some extra long key to encode the exchange of shorter length keys. Why do we need quantum key exchange?
Some drink at the fountain of knowledge. Others just gargle.
So in practice, a hacker *will* steal them while they are briefly vulnerable. Or when the keys are generated. Or use a flaw in the RNG to reduce the search space and crack it with his own quantum computer.
But please, yes, DO tear out the old infrastructure ASAP, and replace it with 5G wifi broadcasting every keystroke, and ultra-thin client screenphones that harvest biometrics and private info and store them in the flaky, unreliable "QUANTUM CLOUD", where they can be properly traded and monetized, then subsequently lost or stolen.
enough said :(
[($)]
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The QKD approach used by Quantum Xchange works by sending an encoded message in classical bits while the keys to decode it are sent in the form of quantum bits, or qubits. These are typically photons, which travel easily along fiber-optic cables. The beauty of this approach is that any attempt to snoop on a qubit immediately destroys its delicate quantum state, wiping out the information it carries and leaving a telltale sign of an intrusion.
Maybe if I'm a bad guy, I'm quite OK with that. That would be something like a DDOS. Maybe I don't care about trying to steal your quantum encrypted data but I want to deny your ability to transfer data that way so you will move to a method of transmission I can read.
At nodes, keys are decrypted into classical bits and then returned to a quantum state for onward transmission. In theory, a hacker could steal them while they are briefly vulnerable.
Believe me, bad people will certainly do this. One of the ways Blu Ray encryption got cracked is that the players stored the keys unprotected in memory and smart people figured out how to dump the memory to get the keys. National actors who really want access to your data will have no problems trying to attack this weak point in the chain.
The important part of quantum encryption is that a single photon cannot be measured completely so that an attacker cannot read the quantum communication and then send it out again. If the attacker tries, then when the two parties compare part of the secret key, it won't match. The secret key is then used as a one-time pad to send encrypted messages. So far, so good.
Authentication is needed to make sure that the measurement basis (what angle the photon polarization was measured in, and sent classically rather than over the quantum channel) was sent by the sender and not the eavesdropper. Since this authentication will use regular encryption, the quantum part is fairly useless. If the authentication uses a one-time pad, then the two parties already had a one-time pad and could have skipped the quantum part. If the authentication uses classical encryption, then the two parties might as well have used classical encryption to send a one-time pad.
The Quantum Key exchange is interesting but not really practical. The equipment is expensive and hard to set up. Further, if you are using photons you can only send one per quantum state. If you send more than one an attacker can intercept them and figure out their state.
In the easiest example Alice sends photons either polarized (up/down / side-2-side), or diagonally. Bob will then tell Alice which way his detector was set up for each received photon. For the photons his receiver was correct he know the polarity of Alice's photon. Alice and Bob then have a shared secret to use as a key. If Eve intercepts the photons she has to both read the photons and pass them on to Bob. If her detector is set up on the diagonal and Alice sends an up/down polarized photo Eve won't know the polarization and can't send the correct photon on to Bob. However if there are multiple photons, Eve can split them up and test them individually. With 8 photons Eve has a 63 in 64 chance of knowing the photons polarity and 255 out of 256 chance of fooling Bob well enough for her attack to go undetected.
For the entire thing to work either you have to send multiple photons and have them boosted or you send one and the repeaters know Alice's pattern of polarization. In the second case this pattern becomes a key that must be kept secret across every repeater. You may as well just give Bob this key.
It could still be used for shorter links, but yes, a single repeater and the whole thing is insecure.
China has succeed achieving this years ago and from space too. When have American scientists got in the culture of making false and exaggerated claims?
First, Quantum Modulation (no, it is _not_ encryption) has been broken time and again by simply attacking the implementation instead of the theory. Anybody that thinks this stuff must be absolutely secure is utterly naive with regards to technological reality. Second, the theory used to claim "absolute security" is known to be flawed (still no quantum gravity). And third, conventional encryption is far superior in handling, reliability, cost, etc. and gets the job done just as securely, even if in 50 years or so we may have to go to post-quantum encryption (or not).
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
Not if they choose a k-n quorum scheme among k nodes on a network.
Alice and Bob want to agree on a key. Alice can send photons polarized at 0, 45, 90 or 135 degrees. Bob will have a detector for 0 or 45 degrees. If Alice sends a photon at 90 degrees and Bob uses the 0 degree receiver then Bob gets nothing but if he uses the 45 degree one he gets a photon 1/2 the time. So when Alice sends at 90 or 0 degrees Bob only knows for sure what the polarization was if he used 0 degrees. Alice will send 1000 photons this way. Bob will create a list of 1s and 0s depending on whether he detected the photon. Bob will then send back a list of how he had his receiver set up and then Alice will send a list of the times Bob was correct (i.e. he used a receiver that was the same or 90 degrees off). Alice and Bob now both know the list of 1s and 0s that Bob created when his detector was correct.
Now Eve, who is in the middle and trying to intercept the photons, must set up her detector to guess the polarity but the best she can do is guess like Bob did. She has no idea when she guesses correct and she must send a new photon on to Bob. If Eve's detector is at 45 degrees and she detects a photon then either the photon was sent at 45 degrees or it was sent at 90 or 0 and this is the 1/2 chance it was detected. The probabilities for each polarity {0, 45, 90, 135} are {1/4, 1/2, 1/4, 0}. She could then send a photon at 45 degrees. But she has a 1/2 chance that Bob will have the correct orientation, a 1/2 that she had it wrong and change the photon and a 1/2 chance that Bob got the wrong result (her new photon is 45 degree off the original). So Alice and Bob can detect Eve 1/8 of the time.
Now if Alice sends bursts of polarized photons, say 8 or 16 at a time, then Eve's probability of figuring out the true polarity becomes much greater and her chance of being caught drops significantly unless Alice and Bob send tens of thousands of photon bursts.
Conventional encryption is rarely the security limit in real world systems. Much more often it is human factors where there is either an inside job, or a human is tricked by another human into doing something that breaks encryption.
"Hi Carl, this is Alice from IT and it looks like the quantum link has de-phased again. Could you help phase it by typing the following into your terminal......."
The technology is interesting, but I don't see a situation where it will actually help.
Not quite. There is no such thing as lossless energy usage. The best you can do is Landauer's principle which states you need Boltzmann constant times the temperature to flip a single bit. Given a temperature of 3 Kelvin (any colder and you need energy to bring the temperature down) the best you can do is 5x10^-23J per bit flip. Now we can do some assumptions and hand waving and say we only need to flip on average, from an external viewers perspective, 2 bits per key we try so 10^-22J per key. Also assume we guess the key in the first half of the ones we try means trying 2^255 keys. 2^255~10^80. So we need 10^68J. The Sun's output is 3.8x10^26W. So we need 10^68J/ 3.8x10^26W = 2.6x10^41 seconds. A year is 3x10^7 seconds. A sun like ours can burn 10^10 years so we need 10^24 suns. There are 10^21 stars in the observable universe. So we need 10^3 universes of suns to crack a 256 bit key.
However the above post completely missed the point of the QKE. The point is to exchange a key securely. You could have 1024 bit symmetric encryption if you want, it won't help you exchange the key.
"no expert on quantum computing"
That's OK, neither are they. You cannot actually buy this kit. If you Google it nobody will try to sell you it.
You can simply interfere/intercept the "successful entangle photon" signal (which is filtering) and swap in your own for either end. i.e. you can stick in your own repeater, and MITM traffic.
I don't quite get the point of this. Funding?
It's called "public key infrastructure" and "asymmetric encryption", exists over 40 years already, widely implemented and used. Unlike "bluetooth", adding "quantum" doesn't magically make everything better.
> The initial leg of the network, linking New York City to New Jersey, will allow banks and other businesses to ship information between offices in Manhattan and data centers and other locations outside the city.
Yeah, they can do it now. Over public internet, without optics and vulnerable repeaters, using cheap off-the-shelf consumer grade devices. This "solution" adds absolutely nothing of value.
> The beauty of this approach is that any attempt to snoop on a qubit immediately destroys its delicate quantum state
This is not "beauty", this is vulnerability.
who needs to securely exchange a key? Just use a public key encryption to transmit the message (the message could be a key for a non-public key encryption)
Some drink at the fountain of knowledge. Others just gargle.