Schneier Calls Quantum Cryptography Impressive But Pointless 233
KindMind writes "Bruce Schneier writes in Wired that quantum cryptography, while an awesome technology, is actually pointless (that is, of no commercial value). His point is that the science of cryptography is not the weak point, but the other links in the chain (like people, etc.) are where it breaks down."
sure... (Score:5, Insightful)
...but as soon as I release my algorithm which factors the products of large prime numbers in log(n) time, they will be begging for quantum crypto.
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Re:sure... (Score:4, Funny)
Re:sure... (Score:5, Funny)
factors the products of large prime numbers in log(n) time
That's easy, just use sqrt(n) computers.
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log in the case of computational complexity is almost always base 2, so that would be 2^n [it's a binary thing]
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In reality, it's always going to be the "endpoints" that are the problem. We still cannot even know with 99.999% certainty that a transaction to a remote application came from a specific user. We use bloated software with tens of millions of lines of code. Even the best err
Re:sure... (Score:4, Interesting)
Re:sure... (Score:5, Insightful)
Yeah, but in any commercially useful application of the technology, you're going to have computers at each end dealing with the data once it's decrypted.
That's Schneier's whole point really. The weak link isn't actually sending encrypted data, it's dealing with the data at either end of chain. For the data to be useful, it has to be decrypted at some point in time, and the listener's computer has to know how to do the decryption. An attacker isn't going to attack the encrypted data stream. They're going to attack either the source or the listener, and either get the stored decrypted data, or get the stored encrypted data and the necessary info to decrypt it.
If your total communications network consists only of a encrypted communications line, plus a computer on each end, and both of those computers have no other connection to any other sort of network, and also have foolproof physical security, then maybe the encryption line might become the weakest point. But in the real world, computers are generally interconnected with many others, allowing lots of directions to attack from.
Unless someone comes up with some amazing breakthrough that makes factoring very large numbers trivial, there aren't really any practical cases where the encrypted data stream is the likely target of an attack.
Re:sure... (Score:5, Insightful)
Taking care of the human and physical security is my business. It's the encryption technology that I can't control / verify. So give me encryption that I can trust and I'll be able to assess my security based on the things that I can control / verify myself. Schneier has no business telling me "your set up is flawed so there's no point in giving you secure encryption." It's for me to judge and all I want is to ensure that no weak links come in from outside my control, i.e. a flawed algorithm or technology.
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So give me encryption that I can trust and I'll be able to assess my security based on the things that I can control / verify myself. Schneier has no business telling me "your set up is flawed so there's no point in giving you secure encryption."
You've missed the point. Scneire's point is that you already DO have "encryption I can trust". His point isn't that "your set up is flawed", his point is that "all setups have weaknesses, and the weakest point is almost never the encryption system." Giving you "m
Re:sure... (Score:5, Insightful)
He's basically telling that we've reached or are close to the point of diminishing returns, where advances in cryptology (newer algorithms or quantum crypto) can no longer be justified based on the increase in cost for these advances versus the % of attacks on existing crypto.
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It's the encryption technology that I can't control / verify.
First of all lets define what is being discussed: Bruce is talking about Quantum Cryptography that is to say a Quantum Key Distribution System.
Now...let's kick your ignorant ass.
A Quantum Key Distribution system isn't really any more under your control or verifiable by you than one that uses SSL. Both can have flawed implementations both are probably way beyond your skill set to verify.
So give me encryption that I can trust
A quantum key distribut
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Re:sure... (Score:5, Funny)
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To do that you'd have to be repeating the number synchronously with me. Ok. I've chosen the prime. Now, go... :)
Who is they? (Score:5, Insightful)
Quantum encryption seems to fill a very particular niche (point to point communications) and doesn't seem to apply well to common encryption use cases (SSL , email encryption etc).
If public key encryption is broken, quantum encryption isn't going to be a good replacement for it for most things.
A billion photons... (Score:5, Funny)
Are now running for their jobs.
Thanks bruce.
Re:A billion photons... (Score:5, Funny)
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Nah, you'll just make them collapse.
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ummmm (Score:5, Funny)
What a pussy. (Score:4, Funny)
What a pussy.
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Er...
"Bruce Schneier knows the state of Schroedinger's cat?"
Re:ummmm (Score:4, Funny)
Er...
"Bruce Schneier knows the state of Schroedinger's cat?"
Actually, he remains ambivalent until someone asks him.
Hard to argue with the general point. (Score:5, Interesting)
My (admittedly layman's) understanding is that, barring dramatic advances in factorization algorithms, or extraordinary advances in the computers running them, classical asymmetric key cryptography is more than adequate(plus the convenient advantages of working over data links that aren't spiffy optical fiber).
Re:Hard to argue with the general point. (Score:5, Insightful)
Re:Hard to argue with the general point. (Score:5, Insightful)
I think your analogy is a little bit off. You've got a front door with a standard lock, a dead-bolt, two chains, and a huge rock sitting behind it for security. Now you're faced with a decision whether or not to upgrade your dead-bolt to a super-duper-heavy-duty-dead-bolt. But, since your wife leaves the garage door wide open 4 days a week and no amount of persuasion will convince her to stop, the decision not to upgrade seems like a no-brainer.
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> wife is dead
Lock door.
> you hear a grue scratching outside
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Locking your door doesn't help unless you have unbreakable windows.
Unbreakable windows don't help unless you have car-resistant walls.
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Re:Hard to argue with the general point. (Score:5, Funny)
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Re:Hard to argue with the general point. (Score:4, Funny)
Made by a big International company - bin Laden Group, based in Jidda.
Works perfectly.
To communicate with you, I am thumping on the walls.
If you are listening, could you please cut a hole in the wall.
An upgrade is necessary - I need air.
Re:Hard to argue with the general point. (Score:5, Interesting)
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The problem is, no matter how good your security is, be it traditional or quantum, people are *always* the weakest link. It is always much easier to compromise a person than a machine. Talk to any of the great computer crackers and they will tell you that they got into more systems using "social engineering" than through their computer skills.
ttyl
Farrell
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Unfortunately, that is true. Which is why Bruce is saying that Quantum Crypto is kind of useless. It's neat, but really geeky, but doesn't make it any more secure.
ttyl
Farrell
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Quantum computers aren't magic. They let you solve one category of previously hard problems. The NSA has been advising against using such problems as the basis for new cyrptosystems for years (stop using products of primes). All common symetric cyphers are safe, and there are good asymetric cyphers to choose from.
Quantum cryptography has little do to with quantum computing, and at this point seems to be an answer looking for a question.
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Plus, their power is only predicted to be amazing against
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That's a little optimistic. We're not even sure whether quantum computing, as generally evangelized, is even theoretically possible yet. It's one of the experiments that will help us select between several interpretations of quantum mechanics.
Re:Hard to argue with the general point. (Score:5, Insightful)
Which is worse: a password that you can remember, or changing passwords every 30/60/90 days to a new password such that you can never keep up, and thus need to write it down *somewhere*?
Sometimes, the very processes intended to make us more secure (by forcing a password change regularly) instead make the entire system less secure (because "I forgot my password" too many times and you'll end up out of a job, so better to write it down than to lose your job!).
Sorry, just griping about new policies at $work.
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My old password was alphanumeric, long, and unrelated to my work, personal life, hobbies or anything else that would go in a brute force dictionary.
Now that I have to change my password every month along with a handful of other requirements my passwords are just a vertical row of keys, once with the shift key once without. Anyone who saw me type it once would know it instantly. Good thing we're more secure.
While I appreciate the spirit of the article... (Score:5, Insightful)
I don't think I need to explain that any further to this crowd.
Re:While I appreciate the spirit of the article... (Score:5, Insightful)
You just spent a million dollars on your uber leet super crypto secure link to transmit your highly classified secret data to your home office. You also wrote the key down on a stickey note on the front of the device and left it posted on your monitor that faces a window. You might as well have used the cheapest encryption available because it isn't a math attack that is going to break it, its stupid user tricks.
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In a very rare disagreement, I'm certain Bruce is wrong.
Either he is wrong, or he's arbitrarily drawing a cutoff line for strong crypto, where it has already reached the maximum strength it ever needs to be.
The reasoning of why he's wrong (at least from the summary) is thus:
At some point in the past, crypto could be cracked.
At some point in the past, communication could be tapped.
It's well-known that communication is tapped. Even closed systems are tapped, and have been since electronic and radio communica
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If this is the holy grail of crypto that it's been described as, then it will never be the weakest link.
Bruce is saying that this technology is not significant in the overall security of things, due to many other weaker links that aren't using quantum key distribution. You can't hold this up as the holy grail, because its importance has already been dismissed in favor of bigger issues. Bruce is saying that these bigger issues occur even with our pre-quantum systems.
I'm saying that due to cost and infrastructure, this quantum system does have a use with those groups that have money and take security very ser
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Yeah, but do you really need quantum crypto? The strongest encryption method is a one-time pad. You've now got easy access to 8GB USB sticks that can hold one heck of a big one-time pad, or 8 slightly smaller 1 time pads. As an individual, who do you really need to communicate very securely with? Your bank? Maybe a few close friends for e-mail?
Create a new type of smart USB device that, given a passphrase, allows you to load up a one-time pad data stream associated with a keyword (say BoA123456789), Given a
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The point of QuantumCrypto is to save our collective asses when Quantum computers capable of factoring very large numbers very quickly become a reality.
Until Quantum computers start to appear at your local NSA branch Quantum Crypto is pointless, but we should always be a step ahead shouldn't we?
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Your point is taken, but sometimes it is still significant to ensure that it is the stupid user trick that breaks your system.
Don't you think the CIA, for example, would like to be extra special certain whether the reason the Russians are breaking all their codes is because they have inserted operatives in high-places, or because they have broken large-prime algorithms?
There is also the problem that, yes, the user is the weakest link, but it is not uniformly so. Tricking one guy will get you one encryp
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Re:While I appreciate the spirit of the article... (Score:4, Informative)
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All quantum crypto does is make it impossible to eavesdrop without being detected. It does not secure the data itself. You still use symmetric ciphers to protect the data, and those are theoretically demolished by quantum computing too.
Basically if we ever get practical quantum computing, ANY "search for solution in large space" problem is deflated, and we may as well give up on crypto entirely.
Re:While I appreciate the spirit of the article... (Score:4, Informative)
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Because if you learn the shared secret (by brute force cracking), and log the communications, you can eventually crack the whole system, permanently.
With quantum key exchange, the shared secret isn't derivable from the key exchange (you use it to verify after connecting, under 100% unbreakable encryption, since it's effectively a one-time pad).
The difference is in forward protection of your data. With normal key exchange, someone can eventually work out the key through brute force or some other means. One
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From what I understand, quantum cryptography only prevents eavesdropping by taking a part of the signal. Nothing seems to forbid a man in the middle attack (take all the signal and reproduce it), or eavesdropping at a router location. Am I mis-leaded ?
You're mis-leaded. Or misled, rather.
This is quantum key distribution, which uses entangled photons to send keys. It is not vulnerable to m-i-m attacks because a m-i-m cannot reproduce an entangled photon. Even observing it breaks it... so you can't even monitor communications.
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It has been and still is true that adept social engineering can break any security scheme, due to the vulnerability of the people involved.
And unfortunately, if you take the people out of the loop, you're letting WOPR become Skynet.
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And unfortunately, if you take the people out of the loop, you're letting WOPR become Skynet.
Then again, "unfortunately" depends on yourwelcome datacompperspective.
I know what to do (Score:3, Funny)
Re:I know what to do (Score:5, Funny)
This is Bruce Schneier we're talking about. Bruce Schneier can decrypt quantum encryption by giving it a stern look.
Learned from Chuck? (Score:2)
I didn't know Bruce Schneier is Chuck Noris' student.
Quantum computing breaks normal encryption? (Score:2)
Solving the wrong problem (Score:5, Interesting)
Encryption is easy. Authentication is hard. Quantum cryptography is a solution of the wrong problem.
So quantum auithentication... (Score:2)
...is obviously what we need. Get to work, Bruce.
Hmm. Sounds Familiar (Score:3)
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Enlighten us... who said public key cryptography was pointless in the beginning?
ObCasinoRoyale [imdb.com]
What Schneier is trying to say: (Score:5, Funny)
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Are you certain about that?
one less cause of defect (Score:2, Insightful)
As far as I know, Switzerland already successfully tested it during last year's elections by transfering voting data from a few selected stations to the voting headquarters. Given all the problems with voting machines, that's a quite obvious area of application. However
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As far as I know, Switzerland already successfully tested it during last year's elections by transfering voting data from a few selected stations to the voting headquarters. Given all the problems with voting machines, that's a quite obvious area of application.
You can still transmit falsified data over a secure connection. In fact, it can be falsified at either end without breaking the security of the connection.
(Not that I'm suggesting there was any falsified data in Switzerland's elections.)
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If security is otherwise strong and kept up, there would be a rather small list of suspects that had access to the voting machines and the data, all known by name, and at least one of them has to be involved.
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QC throws a lot of money and time at a part of the system that really doesn't need the help.
Voting machines are a terrible application for cryptography in the first place.
How the hell do I, even with my degree in electrical engineering, montior what the hell is going on inside a voting machine?
Voting should be done with paper. It's simple and also very difficult to rig on a large scale.
E-vot
Who are the users? (Score:5, Interesting)
Nope (Score:2)
CIA/Banks don't need public key cryptography (which is the only kind quantum computing could break, assuming they ever get it working).
If I was the CIA or a Swiss bank I'd be using 3DES - invented in the 70s and one of the most analyzed algorithms in all of history.
Like he says, the algorithm isn't the problem, it's the people who write choose crappy passwords. This is why the USA eventually dropped restrictions on crypto export - it's much easier to install a key logger or guess a password than to crack ev
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If you were the CIA you'd be using AES as that is the US Government standard.
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Not news (Score:3, Insightful)
Bruce has said this dozens of times before this, and he's right. Quantum Cryptography (or alternatively, Quantum Key Distribution) has no commercial application today, outside of (maybe) a few paranoid and high-security government applications. But the latter can hardly be much of a commercial application, since the existence of a large government market would send a strong signal that governments aren't confident in existing cryptographic algorithms. That would be a bad signal to send.
Furthermore, QKD networks have issues including side channel attacks, where the machinery for transmitting/receiving photons actually leaks information via EM emissions, measurable power consumption, or even sound. In fact, one of the big issues they've had in research networks is that historically the transmission machinery has been noisy as hell.
Sorry, Bruce, you're just plain simply WRONG... (Score:2)
It is far from pointless.
Poor implementation of cryptography and who you trust with the keys being unreliable do not mean that making it stronger has no practical benefit.
*I* can control who I give the keys to. Just because most people/implementations do not does not mean there isn't a reason for better cryptography.
The problem is that cryptography is used for many things that either are not important enough to the person that has the keys for them to protect. If I have the keys, and the only keys to my s
Nope, he's right... (Score:2)
Even 3DES (or variations on it) is strong enough for all practical security problems.
AES was mainly developed because software DES is very inefficient, not because DES was broken*.
It's hard to see a practical benefit to developing new algorithms. Much better to devote the effort to analyzing the existing ones.
[*] Obviously plain 56-bit DES is quite weak these days but 3DES is still secure for the foreseeable future.
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Stake out (Score:2)
Bruce,
Whose attack are we defending from here? And who's being attacked? When you say there's no commercial value and only a few technophiles will use it, do you also include well-funded adversaries and governments in the commercial category -- or are they the technophiles?
I'm sure we all can think of many applications where it's a lot easier to attempt interception than go after the endpoints which would be heavily guarded and/or have highly trained personnel who would die rather than divulge information.
O
It's ok to develop stuff for a small user base (Score:3, Insightful)
About the quantum network demo (Score:5, Informative)
I have been there, and can give my impresson. I think, this is a big milestone for quantum cryptography. This has been the most massive and convincing demonstration of the technology up to the date, nothing like any before. Yet, it seems to have received relatively little press attention.
The demonstration was a conclusion of an European project [secoqc.net] in which several tens of research groups collaborated. The main thing it produced are network protocols for a quantum cryptography network. Several months ago, the plan for this demo was four quantum cryptographic links. However, it was easy to plug any quantum crypto link into the network, so six research groups and one commercial company ended up bringing their systems to Vienna (the latter, idQuantique [idquantique.com], actually contributed three links to the network).
Out of these nine systems, seven performed flawlessly for several days, one worked for half an hour and then died (the secure key produced in the first half an hour was still used by the network; the failure was blamed on a software problem in that system), and one prototype did not quite survive the flight to Vienna (hard disk was trashed by baggage handlers). Given that most of the systems were research prototypes, the statistics actually looks good to me.
Since the network topology [secoqc.net] allowed for redundant paths between most of the nodes, the actual failure of one link and simulated failure of another did not prevent the network from operating. (The network topology on the picture as not quite complete: at the last moment, eighth link and one more node were added off the topmost node.) During the demo, there were shown securely encrypted video links between the nodes, and telephone calls. The video links were encrypted with AES with session keys provided by the network. The telephone calls were encrypted with one-time-pad provided by the network. Resiliency to failures was demonstrated: one link was broken on purpose (eavesdropping was simulated by inserting a polarizer, I think), and a key store in another was exhausted during one of the one-time-pad encrypted telephone calls. In both cases, the key distribution was automatically re-routed through other paths and nodes.
The network software implemented so far requires all nodes be trusted and secure. However, I know that algorithms are under development that would allow secure key distribution in a bigger network where up to a certain percentage of nodes might have been compromised.
The demo was on the first day of the meeting. The other two days were just a very good research conference, with no press attending. (I apologize if I got some details above not fully correct.)
Regarding Schenier's position, I respect it but it might be too short-sighted and grounded. And pessimistic. Remember the famous sayings how many computers the world has maybe a market for (five), 640 kB should be enough for everybody, and so on. Classical cryptography has a nasty property to be retroactively crackable. One can record the encrypted classical communication now, wait until it is broken, decipher. Puff, your old secret is suddenly public. For some types of secrets, this is just not an option. Also, Schenier conveniently misses the fact that one can use one-time-pad with quantum key, the combination IS unbreakable, and quantum key distribution speeds steadily improve.
A final remark, there appear to be three commercial companies actually selling quantum key distribution equipment:
The point of pointless research (Score:3, Insightful)
...is actually pointless (that is, of no commercial value)...
It's an interesting definition of "pointless" he's got there; symptomatic of the ultra-capitalistic mindset that has just been demonstrated to be far from optimal by the current financial crisis. Look at it this way: He is saying that the only thing that matters in the world is whether you can make a profit. This is the ideological basis for such things a the lack of regulations that have brought us the crisis; it is also the reason why making a fast profit has been giving priority over long-term financial stability in so many companies, banks not least.
Apart from that - basic research is not pointless, even if there are no short-term profits to be made. Basic research is necessary because we are not able to tell what we are going to need to know in the future - take the early research into quantum mechanics. It was basic research, utterly pointless according to this definition, but we wouldn't have semiconductors today, and thus no PCs nor the endless numbers of electronic gadgets we have now, were it not for that "pointless" research.
It really is time to stop dreaming about "the market" as something magical that will sort everything out for us without requiring us to think and take responsibility.
Re:Quantum Key Exchange not Quantum Computing (Score:5, Informative)
That's what I was thinking as I read a bunch of these posts. The only thing quantum computing and quantum encryption have in common is the word "quantum."
Quantum computers use the superposition of states to form qubits used to do computations using multiple numbers at the same time.
Quantum encrypting uses polarization of light and different alignments of filters to communicate a shared key used to encrypt data. If someone's listening in, they will disturb the polarization causing red flags to go up during the communication of the key. That tells you it's not safe to transmit the message. Furthermore, even if you did, it would just be garbled anyway.
The downside to quantum encryption is that you have to have an uninterrupted fiber optic line from one point to the other. If, at any point, that line has to go through a switch of some sort, you now have a weak point in the encryption where someone can be listening in without you knowing.
It's probably important, too, to point out that we have both quantum computers and quantum encryption. However, the current quantum computers don't have nearly enough qubits to be a threat to public key encryption and the single fiber optic line constraint of quantum encryption is holding it back.
Until quantum computers have thousands of qubits and are easily obtainable, we don't have much to worry about anyway.
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But of course that's what they'd want you to think, isn't it?
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Shut your mouth!
I think you need to read some facts about Bruce Schneier!
http://geekz.co.uk/schneierfacts/ [geekz.co.uk]