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Swedish Researchers Break 'Unbreakable' Quantum Cryptography (eurekalert.org)
New submitter etnoy writes: Quantum key distribution is supposed to be a perfectly secure method for encrypting information. Even with access to an infinitely fast computer, an attacker cannot eavesdrop on the encrypted channel since it is protected by the laws of quantum mechanics. In recent years, several research groups have developed a new method for quantum key distribution, called "device independence." This is a simple yet effective way to detect intrusion. Now, a group of Swedish researchers question the security of some of these device-independent protocols. They show that it is possible to break the security by faking a violation of the famous Bell inequality. By sending strong pulses of light, they blind the photodetectors at the receiving stations which in turn allows them to extract the secret information sent between Alice and Bob.
It just shows that nothing is unbreakable or at least, it tends to prove it.
Everything I write is lies, read between the lines.
The point of quantum crypto is to be able to detect whether someone is eavesdropping on you. Blinding detectors is kind of a tell-tale sign that something is wrong and parties should stop transmitting.
Electronic quantum computing, quantum key distribution all boondoggles and distraction.
Optical quantum computing has far more capacity for scaling, but that gets next to no (public) funding. Funny how that works.
"Quantum key distribution is supposed to be a perfectly secure method for encrypting information. Even with access to an infinitely fast computer, an attacker cannot eavesdrop on the encrypted channel since it is protected by the laws of quantum mechanics. In recent years, several research groups have developed a new method for quantum key distribution, called "device independence." This is a simple yet effective way to detect intrusion. Now, a group of Swedish researchers question the security of some of these device-independent protocols. They show that it is possible to break the security by faking a violation of the famous Bell inequality. By sending strong pulses of light, they blind the photodetectors at the receiving stations which in turn allows them to extract the secret information sent between Alice and Bob."
First of all, quantum key distribution is not a method for encrypting information. As its name judiciously indicates, it is a method to securely exchange encryption keys. This is not the same thing at all.
Second, the speed of the attacker's computer has no role in this attack and quantum key distribution has never claimed a code is unbreakable since there is no code to break here.
Third, quantum key exchange is a protocol, not a cipher. It relies on quantum mechanics features to tell Alice or Bob the just receive key is compromised or not since it is not possible for a man in the middle to observe the key without being noticed. That is the idea behind this mechanism. Once keys are securely exchanged between both parties, a classically encrypted communication can take place between both parties.
Of course, if you are blinding the receiver, it may be possible to tamper with the key, however, the blinded party should notice it has been blinded. The whole thing rests on very low luminosity photons exchange. If the light beam is too strong, it clearly no longer depicted the quantum characteristics needed to secure the key exchange. I don't really see where the problem is here since it is easy to determine the exchange can no longer be trusted due to high luminosity.
And finally, it seems to me this is old news.
Achille Talon
Hop!
Why are people always picking on Alice and Bob? All they want to do is live in peace, but they're thrown into black holes, sucked into whirlpools, and subjected to all sorts of unimaginable things.
When will they figure we are all plying games with them, and they believe they are talking in secret about secrets, secretly.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Too bad FBI director James Comey doesn't read /. He'd see how insecure even the most thuoght to be secure secure things - like backdoors - are and perhaps lose the impulse to make things even less secure and start moving in the other direction.
You know, it's possible that somewhere in the FBI there's one highly capable James Corney who is right now mopping floors in the basement because every time he and James Comey were evaluated by their superiors, personnel mixed up their reviews, owing to an unfortunate choice of fonts on the review forms.
... allows them to extract the secret information sent between Alice and Bob.
See something, say something people ! - geesh.
It must have been something you assimilated. . . .
Because fuck Alice and Bob, that's why. How dare they keep me out of the loop!
A few nations do not have a lot of hardened mil only networks. They have to use public telco networks passing into a lot of other nations domestic infrastructure thanks to competition policy and trade deals. :)
The way around having to use very public, foreign owned networks and satellites sourced from many different providers for gov and mil communications was often thought to be emerging quantum cryptography.
Australia is spending huge amounts of time, funding and effort to try and keep the idea of national public/private networks open to its very secure mil and gov communications needs.
An Unbreakable Code (24/08/2006)
http://www.abc.net.au/catalyst...
Real gov and mil networks or risk a new Engima 2.0 on public networks due to cost cutting and really having faith that quantum cryptography was good enough
Domestic spying is now "Benign Information Gathering"
"Third, quantum key exchange is a protocol, not a cipher. It relies on quantum mechanics features to tell Alice or Bob the just receive key is compromised or not since it is not possible for a man in the middle to observe the key without being noticed."
Strip off all the wibbly wobbly QM stuff and its very simple:
Alice and Bob send each other photons that are polarized and measure each others photons based on the polarization of the photon they sent.
Since you tell the direction of polarized light by shoving it through a filter, or some similar destructive method, it would affect the key exchange.
It's a key exchange done by sending polarized light.
You can man in the middle it, by breaking the fiber, and Alice exchanges the key with Fake Bob, and Bob exchanges the key with Fake Alice. Different keys exchanged with the attacker, and he man in the middles.
Quantum Key Exchange does not use 'entanglement', which is claimed by Yin to be > 10,000 times faster than light, and the photon is not in some fuzzy undefined state till the sender measure it. That's just obfuscation here.
Does anyone actually use this?
It's tempting to believe nobody would break a fibre optic and insert a tap, but the fiber IS broken at repeaters anyway, so it definitely is trivial to "man in the middle" this, you just change the repeater to be the attackers repeater!!
Back in 2010, it had already been provable that you can intercept, without either end know you had done so.
http://www.technologyreview.com/view/418968/commercial-quantum-cryptography-system-hacked/
This has a strong smell of déjà vu. Something is secure within a domain of application. Attacker push the system outside of domain of application.
I am almost certain I did read something similar several years ago with quantum crypto and blinded receptor
I just knew Alice was up to something with Bob.
That fucking skank whore...
Left MS Windows for Linux Mint and never looked back!
Vote for Bernie in 2016!
With the available information it is impossible for technical people like those that read SlashDot to make sense of anything. There is either the paper itself, which would require slogging through dozens of other papers to even make sense of it, or there is journalistic fluff that is completely meaningless. When you write for an academic audience in your discipline area you should be terse and obscure. But not for a general but technical audience.
My understanding of Quantum encryption is that two qubits are produced at the same time and one is sent to the encrypter and the other to the decrypter. Detecting them destroys them, defeating Eve the eavesdropper.
More importantly the process of creating these produces random qubits and they cannot be created to a specific pattern. Thus they cannot be regenerated in the same pattern that they were created, making like hard for Mallory the man in the middle.
There still needs to be some sort of digital signature to detect Mallory. But the argument goes that that would need to be broken in real time, and Quantum encryption is all about reading the back traffic.
So which part of that story have you attacked? And leave out the bits about the Frigembroten Sniggens defrobulation principals.
"It's mostly rumours, I haven't seen any system in use. But I know that some universities have test networks for secure data transfer," says Prof Larsson.
OK so this is an issue?
Consider this. Big Bang Theory.
0) Incomprehenisible time happens
1) Stars in Universe
2) Incromprehensible time happens
3) Sun exists
4) Jupiter comes into orbit of our Sun
5) Incromprehensible time happens
6) Planet by planet come into orbit of our Sun as if pinball happens
7) Incromprehensible time happens
8) Craters exist on Earth, caused by ?
9) Incromprehensible time happens
10) No oxygen in space, but exists on Earth now. From where?
11) Incromprehensible time happens
12) People now.
Thank you God.
And apparently nobody donated. Your point relevant to this story being...?
Il n'y a pas de Planet B.
If someone tells you they have an unbreakable cryptographic method, they are either lying to you or they're too stupid to know any better.
Advice in a course I had from NSA over 30 years ago.
Laws of quantum mechanics my foot. There's still a method, there is still secret info and if Alice can convey that key to Bob, some other party can get it too.
"Even with access to an infinitely fast computer, an attacker cannot eavesdrop on the encrypted channel since it is protected by the laws of quantum mechanics."
No method of quantum encryption is truly secure. The problem with these methods of quantum encryption is that they take too narrow a view of quantum physics and do not deal with the potential for attackers also using quantum techniques. If your quantum system has more energy and the right configuration it should be possible to break virtually any quantum encryption. - Many or most mathematical encryption methods are also vulnerable to the same methods for the same reasons.. Capture an encrypted source and it inevitably contains an information interference pattern leading to the key, it is merely a matter of devising the right geometry to break the barrier between source and destination.. This is because quantum fields in some models can go faster than light and the FTL geometry represents a point where the quantum system becomes fully deterministic.
The technology to use this is probably still ten to twenty years away though so it is not an immediate concern.. - Might just be possible that some secret military lab in the US can already do it, but very unlikely..
Below the speed of light Special Relativity is one of the most accurate theories in physics - above the speed of light..
I can't speak for Alice, but I'm getting sick and tired of having to do half of the encryption in the world. Most of the time it's just Lorem Ipsum anyway. I do this by moving rocks around in a desert, you know. It's not fun.