Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Quantum Cryptography Leaving the Lab

Hemos posted more than 10 years ago | from the but-leaving-it-very-slowly dept.

Encryption 345

Theodore Logan writes "More than a year ago, MagiQ announced the world's first commercial quantum cryptography system (pdf), with ID Quantique following closely in their footsteps. Currently, the technology is limited to offering point-to-point connections up to a maximum distance of around 50 km, but this is likely to be greatly improved on in coming years. The systems available today are prohibitely expensive for the average Joe (MagiQ's are priced at more than $50,000 per unit), but one could envision a future in which they are built into the infrastructure by non-end user actors. Does this spell the end of the field of cryptography? Will systems like this ever become commonplace, or will they be reserved for sensitive financial transactions and military applications? What impact will quantum cryptography have on society? Good articles available from International Herald Tribune, EE Times and CNET."

cancel ×

345 comments

Sorry! There are no comments related to the filter you selected.

It's worse than that, it's physics Jim (5, Informative)

Space cowboy (13680) | more than 10 years ago | (#8837601)


Since they make a point that they "Rely on the laws of physics", they're bound by them too (maths is far more forgiving :-). Both systems rely on the quantum state of photons being undisturbed, so they can only be used between point-to-point optically-networked devices assuming the act of optically switching the packets has the same effect as reading them (the quantum state will be lost). If this is true, no secure networks could be mass-produced using this, unless you trust all the intervening nodes...

OTOH, it's the first generation of these devices, and perhaps IPv8 will somehow encode an encryption hierarchy (packets get encrypted sequentially in one direction, and decrypted on the way back, assuming the same route is taken, each node only needs to know the encryption to the next one worked ok to guarantee the encryption was ok. You'd still want to be in control of all the nodes along the way though...)

As for price - if they can solve the networking issue, that'll come down dramatically - it'll be onboard in the equivalent of the BIOS that we have in ten years time (when we all have fibre to the home. Possible optimistic :-)

Simon

Re:It's worse than that, it's physics Jim (5, Insightful)

TedCheshireAcad (311748) | more than 10 years ago | (#8837665)

It's nice for creating secure point-to-point links, but that's only roughly half of data security. Transmission security is great, but what happens when someone steals the hard drive out of the server?

With all due respect to the quantum guys, the traditional byte-crunching cryptography kind of has the market by the balls here.

Re:It's worse than that, it's physics Jim (5, Insightful)

jbf (30261) | more than 10 years ago | (#8837686)

Being a networking geek as well as a security geek, I'll point out that the way Internet routing currently works, based on the commercial nature of the Internet, means that almost no routes are symmetric. This is because policies like hot potato routing, where one provider tries to get rid of a packet as quickly as possible. For example, if Sprint and UUNET have exchanges in San Francisco and DC, and a packet goes from a Sprint customer in Sacramento to a UUNET customer in Baltimore, the packet from Sac to Baltimore will go Sprint to San Fran and UUNET the rest of the way, but the return packet will go UUNET to DC and Sprint the rest of the way.

Also, hop-by-hop security is not end-to-end security, so even if you do have all the routers in IPv8 using hop-by-hop encryption over petabit links, you'll still need end-to-end security.

So to answer the question in the post, unless you can afford a leased line with a single fiber, and that fiber is lossless enough to not need repeaters, this is only for things like financial institutions and spy networks.

Re:It's worse than that, it's physics Jim (1)

dustmote (572761) | more than 10 years ago | (#8837705)

Physics is just applied math anyway, as my friend the physicist says. Seriously though, that has an eerie ring of prescience about it, at least to me - you may be on to something there. Or I may have bad instincts for the future, as evidenced by my bad luck with gambling.

Re:It's worse than that, it's physics Jim (3, Interesting)

Anonymous Coward | more than 10 years ago | (#8837716)

Remember its only secure in the sense that you can tell that someone is sniffing the wire (fibre) because a packet (quanta) is altered. It does not stop someone reading this data if they really want / dont care about being known.

You now need to build software on top that shuts down/reroutes the link if its not happy that the route is secure.

For point to point applications (aggregated backbones etc) its great. For general networking
(espicially multiplexed / contention based paradigms we have now) its not such a big deal.

We will have to change the whole protocols, as you say to IP8 or whatever is needed.

I love jews. (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8837602)

Because they're smart, unlike non-jews.

Re:I love jews. (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8837615)

But they have ugly noses and therefore must burn in the furnaces!

Who was the greatest Jewish cook? (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#8837642)

Hitler [resist.com]

GNAA + Quantum Cryptogarphy (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8837617)

our encrypted buttsex movies wont be pirated anymore!

How easy is it to implement ? (5, Interesting)

SloWave (52801) | more than 10 years ago | (#8837624)


I've seen that regular geeks can build things such as quantum force microscopes in their own homes, how hard would it be for someone to build a quantum crypto system?

It's As Easy As : +1, Patriotic (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8837834)


Impeaching The World's Most Dangerous Leader [votetoimpeach.org]

Cheers,
Kilgore Trout

Re:How easy is it to implement ? (0)

Anonymous Coward | more than 10 years ago | (#8837867)

Doubtless there are articles out that explain the construction of such a device, the same cannot be said regarding quantum cryptography, since this company is "leading the breakthru"

Of course.. (-1, Troll)

brokenin2 (103006) | more than 10 years ago | (#8837626)

Of course it will become commonplace. As quantum computing becomes more commonplace, quantum cryptography will have to be. In the end, quantum cryptography will be the only way to secure your data to any reasonable extent.

Re:Of course.. (4, Funny)

Anonymous Coward | more than 10 years ago | (#8837664)

Dude, "quantum stuff" != "other quantum stuff".

Nice attempt to score an easy +5 insightful...

Re:Of course.. (0)

adavies42 (746183) | more than 10 years ago | (#8837708)

The point is that quantum computers break ordinary cryptography, at least prime-based RSA-type stuff. So when everyone has a quantum machine on their desktop, we'll all need quantom crypto, because nothing else will be secure anymore.

Re:Of course.. (2, Interesting)

brokenin2 (103006) | more than 10 years ago | (#8837792)

OK.. sorry for summarising.. but quantum computers can crack conventional encryption in a single cycle. They make it trivial to factor things down to prime numbers, no matter how large. And since this is the basis of most current cryptography, they will obsolete our current cryptography.



Quantum cryptography (at least in under current theory) cannot be cracked, or intercepted, or decoded twice by two different entities. It is the king of the mountain as far as secure goes.



There are huge problems in trying to transfer the information using quantum cryptography in a non point to point situation, but then again, isn't the point of cryptography (most of the time) to keep your communication as point to point as possible?



Some day, the only way to transfer your information completely securely will be to lock that info into the spin of an electron, or the polarity of a photon, and store those in some secure phyisical media. Then transfer that physical media to the intended recipient, and later verify with them that they are the ones that decoded it. It'll be a pain, but it might be the only way to actually be secure in the end.



Hopefully someone finds a way to automate that system to an extent, without losing it's completely secure nature. Optical switching that somehow manages not to touch that photon? Hmm..



In this case though, quantum cryptography, and quantum computing both have a lot to do with how secure your data can be.

Re:Of course.. (5, Informative)

tomstdenis (446163) | more than 10 years ago | (#8837881)

"OK.. sorry for summarising.. but quantum computers can crack conventional encryption in a single cycle. They make it trivial to factor things down to prime numbers, no matter how large. And since this is the basis of most current cryptography, they will obsolete our current cryptography."

This is bullshit. First off, you have to assume that

a) non-trivial Quantum computers can be constructed at all [who says there are not limits?]

b) The time per solution is not greater than a brute force attack.

I mean sure a single cycle AES cracker would be cool. But if the machine took 2^100 years to build who gives a shit?

This type of hype always pisses me off.

To boot as I understand it, QC only "attacks" in sqrt time by meet-in-the-middle approaches. So AES-256 would provide all the security ya need.

Tom

Re:Of course.. (5, Funny)

Amiga Lover (708890) | more than 10 years ago | (#8837672)

I fear the Quantum DRM that'll follow.

Quantum Crypto != Quantum Computing (5, Informative)

ponds (728911) | more than 10 years ago | (#8837791)

Too bad quantum crypto and quantum computing have absolutely nothing in common.

Quantum crypto is a misnomer, it isnt even crypto at all. It's an intrusion detection system. Quantum crypto works by sending sensitive photons through a tight channel as bits which will get disturbed by an eavesdropper. Where as electrical signal on a wire expects static, and a wiretap isnt noticed.

Quantum computing however, works on electron entanglement, and is pretty far off.

Re:Quantum Crypto != Quantum Computing (1, Informative)

Anonymous Coward | more than 10 years ago | (#8837850)

I believe the point he was trying to make is this:

With advances in quantum computing and the potential which it holds, it has the ability to render most encryptions schemes as nothing more than a minor inconvience to someone trying to decrypt the data contained within.

At that point he feels quantum cryptography will be the only method in which to safely encrypt data.

Re:Of course.. (0)

Zoshnell (573838) | more than 10 years ago | (#8837929)

You said quantum waaaay too many times. Who do you think you are, the late Mr. Carl "billions and billions" Sagan?

point to point (2, Funny)

TedCheshireAcad (311748) | more than 10 years ago | (#8837627)

Great, point to point security, but how do I encrypt all my pr0n with it?

Re:point to point (2, Interesting)

Adriax (746043) | more than 10 years ago | (#8837702)

Stick both ends onto your computer with a 49km loop of cable connecting the two. Then just compress your data, and send it through the loop constantly.
Kinda like putting your pr0nship on a holding pattern where no one else can touch it.

Re:point to point (5, Funny)

Rick.C (626083) | more than 10 years ago | (#8837770)

how do I encrypt all my pr0n with it?

I've heard you can use steganography to hide your data in .JPGs ;)

MagiQ server at bargain based prices (4, Insightful)

stecoop (759508) | more than 10 years ago | (#8837631)

So we had a slashdot article [slashdot.org] today about CEOs should be held responsible for security at their organization. Then the law should be written to hold companies responsible for security should be fined 3 x $50,000 = +-$150,000. That would make MagiQ' server a bargain at only $50,000.

Quantum Cryptography (5, Insightful)

Anonymous Coward | more than 10 years ago | (#8837640)

I never understood how quantum cryptography is not vulnerable to normal man in the middle attacks. Anyone care to explain?

Re:Quantum Cryptography (4, Insightful)

AndrewHowe (60826) | more than 10 years ago | (#8837680)

The man in the middle can't reliably retransmit, so can always be detected. Unfortunately, as I see it, this means that he can DOS the connection.

Re:Quantum Cryptography (3, Funny)

Anonymous Coward | more than 10 years ago | (#8838048)

Unfortunately, as I see it, this means that he can DOS the connection.

Er well to do anything at all with a quantum line you need access to the fiber, at which point Denial of Service is most easily performed with a large axe. :->

Re:Quantum Cryptography (5, Informative)

fullpunk (518331) | more than 10 years ago | (#8837682)

Reading datas alter them. So the man in the middle will be detected. I'm not a professional, but I understood that you have to destroy the photon to read its information.

Re:Quantum Cryptography (0)

Anonymous Coward | more than 10 years ago | (#8837710)

Sure. And why can't he just read them and then create new ones having the same properties?

Re:Quantum Cryptography (1)

AndrewHowe (60826) | more than 10 years ago | (#8837782)

The single photons are polarised, so to detect them you need the appropriately polarised detector. As there's only one photon, you can only have one detector, as the "wrong" detector will block the photon (and not detect it). You can only detect half of the photons, so you can only retransmit half.

Re:Quantum Cryptography (0)

Anonymous Coward | more than 10 years ago | (#8837807)

So the polarization sequence would in fact be the key which is used?

Re:Quantum Cryptography (2, Informative)

AndrewHowe (60826) | more than 10 years ago | (#8837882)

Sort of. It's part of a negotiation sequence. Read Xeo 024's qubit.org link, it explains it pretty well.

Re:Quantum Cryptography (1)

Threni (635302) | more than 10 years ago | (#8837749)

>Reading datas alter them. So the man in the middle will be detected. I'm not a
>professional, but I understood that you have to destroy the photon to read its
>information.

Yes - the information is altered - you know you're being watched, so you terminate the transmission or start sending junk.

MEN in the middle works (0)

Anonymous Coward | more than 10 years ago | (#8837764)

If you can get a man in the middle both on the quantum channel and on the public channel then quantum encryption helps fuck all.

Re:MEN in the middle works (-1)

Anonymous Coward | more than 10 years ago | (#8837873)

Dude, get a clue. Don't post stuff like that which doesn't have any factual basis and that you don't explain.

Re:Quantum Cryptography (1)

brokenin2 (103006) | more than 10 years ago | (#8837899)

What if the man in the middle is there from the start, and manages to fabricate the entire connection, and retransmit everything as if he/she originated it?

Re:Quantum Cryptography (0)

Anonymous Coward | more than 10 years ago | (#8837976)

As far as I know, this is possible. But the attacer can't simply retransmit everything, but must make real key excahanges with both parties (and might end up with two different keys for the parties). And after the key exchange the attacker must first decrypt the packets with the first key and then encrypt them with the second key.

Re:Quantum Cryptography (-1, Troll)

Anonymous Coward | more than 10 years ago | (#8837696)

I never understood how quantum cryptography is not vulnerable to normal man in the middle attacks

Call the GNAA and bend over, they'll explain you everything about man-in-the-middle attacks...

Sheesh, why don't you google and find out for yourself?

Re:Quantum Cryptography (3, Informative)

Anonymous Coward | more than 10 years ago | (#8837698)

The key is sent with a single photon for a bit. A simple way of looking at it is that by measuring (spying) the photon, you unavoidably change it (randomly flip the bit), causing checksums in the protocol to fail and alarm bells to go off. Heisenberg's Uncertainty Principal or something.

Re:Quantum Cryptography (0)

Anonymous Coward | more than 10 years ago | (#8837774)

I believe they are sometimes vulnerable to a man in the middle attack due to the fact that the equipment isn't perfect. Things like reflecting light off the lasers, or the lasers transmitting two photons instead of one.

Re:Quantum Cryptography (5, Informative)

Xeo 024 (755161) | more than 10 years ago | (#8837777)

Here is a nice article I found about it:

The purpose of cryptography is to transmit information in such a way that access to it is restricted entirely to the intended recipient. Originally the security of a cryptotext depended on the secrecy of the entire encrypting and decrypting procedures; however, today we use ciphers for which the algorithm for encrypting and decrypting could be revealed to anybody without compromising the security of a particular cryptogram. In such ciphers a set of specific parameters, called a key, is supplied together with the plaintext as an input to the encrypting algorithm, and together with the cryptogram as an input to the decrypting algorithm.The encrypting and decrypting algorithms are publicly announced; the security of the cryptogram depends entirely on the secrecy of the key, and this key must consist of any randomly chosen, sufficiently long string of bits.

Read more here [qubit.org]

Re:Quantum Cryptography (4, Informative)

VCAGuy (660954) | more than 10 years ago | (#8837798)

Essentially, Quantum Cryptography works because of Heisenberg's Uncertainty Principle and a thought experiment known as Schrodinger's cat. Basically, when one of these devices transmits a bit, it does so as a single photon with a known "spin." By observing that photon, you modify the very physical properties of that photon and corrupt the data. The man in the middle has no way to reconstruct the data because he has no way of knowing the given properties of a photon in the seqence. Further, that serves to DOS the connection (becuase the man in the middle cannot retransmit the same quantum sequence), thus causing the units to switch off and declare an alarm.

It's similar to Schrodinger's cat: Schrodinger comprised a thought experiement where a cat was put into a sealed box with a poison and a radioactive atom. In the course of 1 hour, the atom has a 50/50 chance of decaying, thus killing the cat. At the end of the hour, the cat is neither dead or alive, but in a state of flux. It's not until you observe the system that you fix the state of the cat as being dead or alive.

magiq whitepaper (5, Informative)

dave_t_brown (447547) | more than 10 years ago | (#8837815)

Here is a whitepaper [magiqtech.com] from MagiQ on their technology.

Re:Quantum Cryptography (1)

Retric (704075) | more than 10 years ago | (#8837835)

Basically you send 3x the data you need. For each bit you have say a one in 3 chance of reading the value correctly you then send back the photon's who's values you know. You then XOR the data you wish to send and with the values the other side knows and transmit those values out in the open.
If you get over 1/5 of the reads correctly then you know there is no man in the middle of the quantum channel. AKA they can only find out 1/3 of the values to know what to send you and you can only read 1/3 of those values so if you get 1/6th of the photons send there is a problem.
If you get a man in the middle of all communication channels it fails but so does RSA inscription. AKA if I read your key's I can decode the message and then re encode the message with my set of key's send it on and ditto for the back channel.

Re:Quantum Cryptography (1)

Retric (704075) | more than 10 years ago | (#8837939)

Quantum cryptography is vulnerable to normal man in the middle attacks but there are more channels that need to be comprimised to pull it off.
If you intersept the Quantum stream it's detectible asumeing the other streams of comunication were not compromised. But, all forms of encription are vulnerable to man in the middle attacks if you use a well known encription scheem. (Could be wrong on this but if you disagree with me please give from of encription that works if ALL comunications were compromised. Not just the old well we can send a master KEY safely so we can then send our real key's.)

Re:Quantum Cryptography (1)

arr28 (739468) | more than 10 years ago | (#8838045)

I never understood how quantum cryptography is not vulnerable to normal man in the middle attacks. Anyone care to explain?


What most people miss is the fact that there are two channels in quantum cryptography. First, there's the channel carrying the photons (which will become the secure channel following the safe transmission of a one-time pad). Next, there's the channel over which you verify that the one-time pad wasn't messed with. These two channels must not be the same otherwise the classic MITM attack works.

Furthermore, if an attacker can gain control over both channels then the MITM attack still works.

Few quantum crypto books bother to explain this and as a result, few people realise the problems. I predict that if quatum crypto reaches the masses then there will be a high-profile case or two involving this sort of attack before it's all sorted.

Solution looking for a problem (4, Insightful)

heironymouscoward (683461) | more than 10 years ago | (#8837648)

For a niche market, it may be useful. But the mass market is hardly suffering because of weak cryptography.

New technologies gives us a nice warm feeling, but the banal truth is that what most people need is better use of existing technology.

Still, I assume spooks and crooks will be investing heavily in quantum cryptography, and we'll see the first quantum walkie-talkies within 10-15 years.

Agreed (3, Interesting)

Sanity (1431) | more than 10 years ago | (#8837721)

This type of thing will become necessary once sufficiently powerful quantum computers become available, but until then - it is pretty hard to think of any applications for this that more conventional symmetric cryptography such as AES can't address.

Re:Solution looking for a problem (1)

Threni (635302) | more than 10 years ago | (#8837789)

> But the mass market is hardly suffering because of weak cryptography.

Many organisations need to transmit securely. This is one such mechanism. Sometimes you need the best, regardless of cost. IE a one-time pad. But they're a hassle to use properly. This system sounds ideal. If there are no flaws, it's pretty much perfect.

Does this spell the end of the field... (3, Informative)

Anonymous Coward | more than 10 years ago | (#8837649)

Does this spell the end of the field of cryptography?

Uh, no. Quantum key distribution is completely useless unless you have a cryptographic algorithm and protocol using that key for encryption. I suppose you could just send the message over quantum channels, but a quantum channel for key distribution is probably many orders of magnitude too slow for the acutal data.

Re:Does this spell the end of the field... (4, Informative)

gpinzone (531794) | more than 10 years ago | (#8837903)

There's no guessing about the encryption method. It's a One Time Pad. Only the key is sent through the quantum link. After it's received, you can send the encrypted data any way you like. Send it over the Internet though the most insecure channels. It makes no difference as long as the key is secure and non-deterministic.

Re:Does this spell the end of the field... (2, Insightful)

Anonymous Coward | more than 10 years ago | (#8837969)

Er if the link is to slow for the data it is to slow for an OTP key... it has to be the same size as the data.

(Or do they mean that the quantum link will be transmitting OTP key continously..? How will the parties know which part of the key to use? Er ok they could transmit that on the quantum channel too... maybe it could work.)

Re:Does this spell the end of the field... (0)

Anonymous Coward | more than 10 years ago | (#8837937)

Stop starting your messages with "Uh, no." It makes you look like a dweeb who knows too much about Star Trek.

Re:Does this spell the end of the field... (3, Informative)

Theodore Logan (139352) | more than 10 years ago | (#8838037)

Who the hell moderated this informative? QC uses one time pads, and since one time pads are provably secure, that's that. No need for fancy cryptographic algorithms. The "quantum" bit of it merely ascertains that the pad was not read by a man in the middle by making use of the EPR paradox [wikipedia.org] , but other than that, this is the same algorithm as Gilbert Vernam developed more than 80 years ago (which is why one time pads are sometimes called Vernam ciphers).

In the PDF (4, Funny)

Rosco P. Coltrane (209368) | more than 10 years ago | (#8837651)

"No matter what advances occur in digital computing, quantum encryption can never be deciphered, read or copied"

Linux already has an interface that you can move your critical documents to and they'll never be deciphered, read or copied: /dev/null

Like the black hole / quasar relationship... (0, Funny)

Anonymous Coward | more than 10 years ago | (#8837801)

Anything you send into /dev/null comes out in an alternate universe in /dev/random. Don't expect to be able to understand it any more than their universe can understand your /dev/null.

Insensitive Applications (4, Funny)

handy_vandal (606174) | more than 10 years ago | (#8837655)

Will systems like this ever become commonplace, or will they be reserved for sensitive financial transactions and military applications?

Quantum crypto will be very useful for insensitive financial/military applications. Example:

"All right, you worthless son-of-a-bitch -- pay your goddamned taxes, or we blow you away!"

-kgj

First thing that comes to mind... (5, Funny)

DarkHand (608301) | more than 10 years ago | (#8837669)

Freenet: Quantum Encryption Edition

Re:First thing that comes to mind... (0)

Anonymous Coward | more than 10 years ago | (#8837715)

Shit you're funny...

I was watching some TV the other day (0, Interesting)

ObviousGuy (578567) | more than 10 years ago | (#8837676)

A Japanese reporter was able to get an interview with a small Al Queda cell. He asked them how they communicated messages back and forth. The initial way, they said, was over the phone with code words and special phrases. This turned out to be less than adequate and computers, crypto, and the Internet became the primary means of updating Al Queda cells with new information. However, since the fall of Afghanistan the computer systems that Al Queda used at the home base have all been destroyed or confiscated by American troops.

So what do they do now? Courier. Someone physically carries the message from person to person and is capable of destroying himself and the message at any sign of danger.

If your data is so important that you need this level of crypto, try to remember that all it takes is a very determined person to come in and steal the machine. Crypto is one of those feel-good technologies that costs people a lot of money but doesn't really do much for anyone in the end.

Re:I was watching some TV the other day (2, Funny)

Rosco P. Coltrane (209368) | more than 10 years ago | (#8837752)

Crypto is one of those feel-good technologies that costs people a lot of money but doesn't really do much for anyone in the end.

Okay then, why don't you send me your credit card number in plain text then? no need to encrypt it, it's just feel-good technology, and I'm really an honest guy...

Re:I was watching some TV the other day (1)

ObviousGuy (578567) | more than 10 years ago | (#8837773)

I give my credit card number to cashiers in plain text all the time. Most likely you do too.

You, sir, are grossly misinformed (4, Insightful)

sczimme (603413) | more than 10 years ago | (#8837812)


and I can't believe anyone actually modded you up. So crypto is just a "feel-good technolog[y]" and "doesn't really do much for anyone in the end"? Have you ever used a VPN? Or SSL? Or anything in the PGP/GPG genre? Why?

Crypto is not perfect but it is extremely useful in certain situations. You apparently believe that since crypto doesn't solve all of our problems that we shouldn't use it at all.

PS If you think that "a very determined person" stealing the machine will render all crypto ineffective, you need some remedial reading on the topic. (Not a flame - just an observation.) Here is a hint: multi-level security.

Re:You, sir, are grossly misinformed (1)

shadoelord (163710) | more than 10 years ago | (#8837925)

Your assesment seems to lead to the thought that the data / documents are never unencrypted. Why waste time breaking an encyption when you can sniff the signals off the viewer's monitor, or pay an insider to leak sensitive info?

The largest security hole is human error.

Re:You, sir, are grossly misinformed (0)

Anonymous Coward | more than 10 years ago | (#8838004)

what about a determined person with a crowbar & a razor blade? how well is PGP/GPG going to keep you from telling them your password?

It all depends on how 'determined' your determined person is. But, generally speaking you're right. The kind of people who really need this level of crypto usually don't have to worry about getting their data stolen. Mostly because their adversary (or business competitor) can't afford to even be suspected of the theft.

Re:I was watching some TV the other day (0)

Anonymous Coward | more than 10 years ago | (#8837844)

Crypto is one of those feel-good technologies that costs people a lot of money but doesn't really do much for anyone in the end.

Kind of like toilet paper with moisturizer.

Re:I was watching some TV the other day (1)

geoffspear (692508) | more than 10 years ago | (#8837904)

Yeah, if the US military decides that they want to blow the crap out of you and seize your home and all of your computers, encryption won't do you much good.

For the vast majority of us who aren't doing anything that would make the military want to invade and take over the networks we're using, it's fairly effective. But thanks for the reminder that if all the technology I use gets destroyed, I should switch to a courier who's willing to die to keep my Quicken data secure.

Re:I was watching some TV the other day (1, Redundant)

Theodore Logan (139352) | more than 10 years ago | (#8837930)

If your data is so important that you need this level of crypto, try to remember that all it takes is a very determined person to come in and steal the machine.

Unless the hard drive is encrypted, that is. Which, I suppose, is one out of many answers to my question in the write up regarding the potential future obsoleteness of traditional cryptography. QC is good for quickly passing secure messages from A to B. But sometimes, B=A, i.e. the intended recipient of the message is yourself. Then you'd probably like to decide upon the speed of delivery yourself, which is basically what a hard drive is for.

Re:I was watching some TV the other day (2, Insightful)

Comatose51 (687974) | more than 10 years ago | (#8838083)

Obviously everything we use involves trade-offs. The more secure it is, the more difficult it is to use. Having a human courier might be very secure but I doubt Internet commerce would be where it is today if that's all we used. You have to weight the benefits and the costs. A blanket statement like that is silly. At some point, we have to decide that even if a technology is not absolutely secured, it is good enough. Whatever lost we might experience is offset by the gains. This is why we continue to use imperfect technology. If all we do is use the perfect solution, we wouldn't be pass sticks and stones in our development.

Explain this to me please (1, Insightful)

Anonymous Coward | more than 10 years ago | (#8837679)

Many scientists have foretold the end of RSA with the advent of quantum computers. With these super fast computers you could factorize any prime within an acceptional window.

So why can't we use quantum computers to generate HUGE (really HUGE) primes so that even quantum computers won't be able to factorize easily?

Because linear key improvement isn't an advantage. (5, Informative)

expro (597113) | more than 10 years ago | (#8838003)

The reason most encryption works is because when you linearly increase key size, you exponentially increase the amount of time required to crack the key if you have no special knowledge, meaning it is much more difficult (impossible for practical purposes) to decrypt without a key than encrypt or decrypt with the necessary keys.

Doubling the key size may only double the work of the one encrypting and decrypting using a key but exponentially increases the work of the one trying to break it without a key. Almost no matter how easy it is to crack a short key, you can increase key size until the advantage of linear versus exponential is overwhelming.

But quantum computing -- encoding the problem into the quantum matrix, not to be confused with the quantum encryption described in this article -- threatens to be able to solve such problems in linear time instead of exponential time.

This means that when the user doubles the size of his key instead of exponentially (enormously) increasing the amount of work to solve the problem, it only doubles the amount of work required to crack it, which would make decryption a simple footrace even if you do not have the key, if the amount of work required to crack the key is proportional to the amount of work required to encrypt / decrypt instead of an exponential relationship.

Primes would not seem to be adequate at all, if quantum computing allows them to be solved linearly. At best, if you could find something that had the difficulty of non-quantum primes under quantum computing, then perhaps you could use that.

Re:Explain this to me please (1)

Retric (704075) | more than 10 years ago | (#8838050)

The assumtion to RSA encription is that it's exponentualy harder to factior numbers as there size increases. AKA find prime A computation time N find prime B computation time N. Factor AxB into A and B takes N*N.
But, with quantom computers it might not take N*N as long. AKA if factoring a 128bit key takes as long as factoring a 256 bit key then RSA is useless.
What everyone seems to forget is while it does not take longer the signil strength decreases exponentialy. (AKA you build a 4 bit QM prototype and it works well an 8 bit part needs to be 16 times as sensitive. And you need to build it so it reads the entire number and factors it in one step. So someone builds a 128 bit QM then you need to have a 256bit QM which needs to be 2^128 times more sensitive.) AKA you can't factor the first 64 bit's of a number then the second 64 bit's...

Quantum Cryptography is for Faggots (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8837700)



And charlatans!

Link Security (2)

silas_moeckel (234313) | more than 10 years ago | (#8837742)

All this is in link security it wills top people from tapping into fiber between endpoints (currently 50km not exactly usefull distance) this might be usefull for a paranoid campus setting or for military short distance communications. It would be nice for point to point open air laser links (I think it can be applied to that dont see any reason it cant but not 100% sure) But overall this dosent realy do much of anything usefull beyond that. I would hope they are working on longer distances though it would seem that since the quantum stuff is allways in sync and has little do to with speed of light while the laser light does have those issues so it would seem like a timing issue, again though in quantum physics I'm just an interested observer.

Re:Link Security (1, Insightful)

Professr3 (670356) | more than 10 years ago | (#8837901)

The cool thing about quantum entanglement is, if you even look at the data in the middle, you remove the probability elements from the quantum states (in effect) which is easily detectable from the other end. In other words, there's no real way to perform a man-in-the-middle attack.

Re:Link Security (1)

silas_moeckel (234313) | more than 10 years ago | (#8838091)

I would disagree with that. Pretty much it works as two matched black boxes. You can perform a man in the middle attack by intercepting a box or otherwise replacing a box. You then insert insert into the path one of the origional boxes and the pair for the replacement box and you end up with the "clear text" in the middle. It's just hard to perform a man in the middle attack. The nice thing that yes you can detect monitoring in the middle. You know it would be funny when these thigns go onto some of the longer lines replacing existing long haul data and voice routes how many have taps.

Uh Oh (5, Interesting)

nate1138 (325593) | more than 10 years ago | (#8837751)

said Bob Gelfond, founder and CEO of MagiQ Technologies. "No
matter what advances occur in digital computing, quantum encryption can never
be deciphered, read or copied.


These kinds of statements always amuse me. It may be the toughest thing yet, but there's no saying that our understanding of some of the properties of quantum physics aren't flawed. Science may yet prove him wrong.

Re:Uh Oh (2, Insightful)

jponster (750086) | more than 10 years ago | (#8837808)

but what if you have a quantum computer? surely this would break all conventional encryuption, but can a quantum computer beat quantum encryption?

Anyone for a game of "Cryptographic Top Trumps"??

naive (2, Interesting)

Rotting (7243) | more than 10 years ago | (#8837781)


I will be the first to admit that I am somewhat ignorant in this matter. My understanding is that current crypto systems rely on the fact that keys take an extremely long time to be brute forced because currently computers are not efficient at all at factoring.

As I mentioned before I am ignorant when it comes to this but doesn't it seem a little naive to say that their technology is 100% secure? I read the pdf and it sounds impressive but I still don't know about anything really being 100% secure for all time.

Re:naive (1)

Rotting (7243) | more than 10 years ago | (#8837906)

To clear things up a little...

What I was trying to say is maybe MagiQ might have been better off saying their quantum crypto system is "currently the best there is" as opposed to saying their system is "100% secure".

Once quamtum computers are the norm, might there be a possibility that someone will find a way around their security system?

Re:naive (1)

DR SoB (749180) | more than 10 years ago | (#8837984)

Actually when they say 100% secure they are talking about the fact that as soon as someone tries to intercept the message, it changes the photon arangement of the atoms, and they can instantly detect it. Making it 100% secure in the fact that at least if they do intercept it and are able to decrypt it, you will know real-time. So in this aspect it is secure, until the average joe can do what they do that is, and start re-arranging photon's themselves, so they could read it, then just re-create it and send it on it's way un-altered. Give it another decade or so and this will be childsplay to late latest script kiddies..

Re:naive (1)

Rick.C (626083) | more than 10 years ago | (#8837980)

My understanding is that current crypto systems rely on the fact that keys take an extremely long time to be brute forced because currently computers are not efficient at all at factoring.

From the article:
"MagiQ Technologies, Inc., the quantum information processing (QIP) company, today announced the general availability of its Navajo Secure Gateway, the world's first commercially available quantum key distribution (QKD) system."

Note that this product makes no claim for more than secure key distribution only, not for general data encryption. You pick your own encryption method and MagiQ will make sure your keys get from here to there securely.

Once the keys have been distributed, you use them to encrypt your sensitive data using RSA, triple-DES, etc (pick your own poison). This encrypted data is no more secure against brute force that it was without the quantum key distribution method.

It appears that MagiQ is only guaranteeing that your keys won't get hijacked.

Social Chaos and Anarchy (2, Funny)

bruthasj (175228) | more than 10 years ago | (#8837831)

What impact will quantum cryptography have on society?

It will be the end of us all! I will *never* purchase GMO-computers They will spread into neighboring villages and corporate monopolies such as Consanto will patent with royalties accumulated on a per atom basis.

Oh, the humanity!

Theorys and more (4, Informative)

thogard (43403) | more than 10 years ago | (#8837849)

Quantom theorys are already out of the lab and in the real world. Old computer hardware is based on NAND and XOR gates but Toffoli and Fredkin gates are useful in the modern world and because you can revser them, once you start building DES/AES/RSA engines out of them, you can start to short circut some of the brute force attaces in very interesting ways. Combined with the real world ability to pre-compute and store data sets in the order of 3e12 bytes at a time, there are many crypt attacks now open to anyone with a good collection of hard drives.

Quantum problem (1)

jabbadabbadoo (599681) | more than 10 years ago | (#8837856)

Soon, crackers will use anti-matter to do man-in-the-middle attacks.

I call'em quarkers.

it wont be adopted now (1, Insightful)

virtualone (768392) | more than 10 years ago | (#8837860)

as long as the current internet infrastructure works like this it won't be widely adopted. why? simply because it is a quite expensive way of communicating between n different spots if you have to install n! fiber cables.

Bruce Schneier doesn't care for it (3, Interesting)

Anonymous Coward | more than 10 years ago | (#8837915)

See Bruce Schneier's comments about Magiq and quantum cryptography at Schneier.com [schneier.com] :

To quote:

This isn't new. The basic science was developed in the early 1980s, and there have been steady advances in engineering since then. I describe how it all works--basically--in Applied Cryptography, 2nd Edition (pages 554-557).

I don't have any hope for this sort of product. I don't have any hope for the commercialization of quantum cryptography in general; I don't believe it solves any security problem that needs solving. I don't believe that it's worth paying for, and I can't imagine anyone but a few technophiles buying and deploying it.

It's not that quantum cryptography might be insecure; it's that we don't need cryptography to be any more secure.

Not a question of if, but when (5, Insightful)

dmccarty (152630) | more than 10 years ago | (#8837919)

Every cipher scheme, from the Greeks' steganography [magic-city-news.com] to the Romans' alphabet substitution [thinkquest.org] to today's 3DES [wikipedia.org] and other schemes, has eventually been broken. It's unreasonable to believe that quantum cryptography will be invulnerable to attacks forever. It's not a question of if it can be broken, but rather when it will be broken.

Perhaps someone will discover a work-around to Heisenberg's uncertainty principle, or perhaps researchers will find flaws in the implementation of the algorithm. But if history is any indication of the future, quantum cryptography will eventually be cracked.

First Mainstream Usage (1)

dj42 (765300) | more than 10 years ago | (#8837924)

I suspect the first mainstream application of this will involve watching porn at the office.

What's the use of this? (1, Troll)

Anonymous Coward | more than 10 years ago | (#8837947)

As far as I know, this quantum "cryptography" prevents just passive evesdropping (where the parties are able to notice evesdropping because of this quantum "cryptography"), but as it doesn't include any kind of authentication, active attact (where all the messages are captured and the attacker is able to send his own messages) should be successfull. It is possible for Eve to just hijack all the messages and pretend to be Bob when communicating with Alice and to pretend to be Alice when communicating with Bob.

It is of course possible to make this "cryptography" more secure by using some classical cryptographical methods, like authentication. But if we have rely to public key algorithms (which might become obsolete by advances in quantum computing), then it is not clear to me what is the advantage of using quantum cryptography in the first place. If somebody has answer to this question, I would be glad to hear it.

Solving the wrong problem (5, Insightful)

Paul Johnson (33553) | more than 10 years ago | (#8837948)

Quantum crypto is only useful over point to point for short distances because it relies on properties of photons that cannot be amplified (if they could be amplified then you could clone the signal and the security would be lost). Its also very very slow (kilobits per second at best). The way it is used is as a key distribution system. The heavy lifting of actually transmitting the data is done by ordinary crypto. So its no stronger than the ordinary crypto. The only thing in favour of quantum key distribution is that you can change the key very frequently.

But these days if you want to intercept data then cracking the crypto is one of the last avenues you would try anyway. Far easier to crack the end points, suborn a trusted employee or any of the other common attacks. Security is only as strong as the weakest link. Quantum crypto merely reinforces one of the strongest links.

Re:Solving the wrong problem (1)

Blaskowicz (634489) | more than 10 years ago | (#8838035)

you could use it to transmit your über top secret plain text too!?

won't the Government just make this illegal? (3, Insightful)

RiotXIX (230569) | more than 10 years ago | (#8837949)

I wouldn't be surprised if the Government prevented this from becoming common place: I remember them doing something like this before, where they wouldn't allow 40-bit encryption system for the public (or something like that), because it meant the NSA couldn't crack it in a reasonable time. Privacy is illegal. If the government can't tap your phone calls and read your e-mails, then they won't allow the public to use that technology. Or at least until the war on terrorism ends (should be sometime around the extinction of human nature and mankind).

What the hell?.. (2, Funny)

Chitlenz (184283) | more than 10 years ago | (#8837965)

Is a non-end user actor?

For some reason I have this vision of Gary Bussey making a drug deal...

heh - chitlenz

How quantum crypto works (5, Informative)

ColonelPanic (138077) | more than 10 years ago | (#8837994)

(Based on memory of Bruce Schneier's description in Applied Cryptography)

Alice sends Bob a series of polarized photons.
There are four possibilities: -, |, /, and \.

Bob sets up his polarization detector randomly so that each "qbit" is measured either for horizontal/vertical polarization or diagonal polarization. If a - or | photon hits the detector and it was set up for horizontal/vertical, he gets a good bit, otherwise a bad bit. And if a / or \ photon hits the detector and it was set up for diagonal polarization, same story. The key point is this: if the detector was set one way and the photon is polarized the other, it is in principle impossible to know its true polarization.

So Bob has a sequence of photons, some of which he knows, and some he doesn't, and he knows which are which. He sends Alice a clear-text message saying which ones he knows. Alice then encrypts the true plaintext by XOR'ing it with the values of the photons that Bob knows, using some convention like "- and / are 0, | and \ are 1".

Example:
Alice sends...: - \ - | / - | (random)
Bob's detector: + + X + X X + (random)
Bob's result..: - ? ? | / ? |
Bob's response: 1 0 0 1 1 0 1
Key...........: 0 1 1 1


If Eve tries to listen in on the photons Alice sends to Bob, she perturbs them irrevocably.

A bad description -- go buy Bruce's book for a better one.

A way to break it? (3, Interesting)

Enigma_Man (756516) | more than 10 years ago | (#8838029)

I was looking at this, and reading about it, and read how you cannot determine the state of the photons without changing their state, so someone cannot "watch" the photons fly past without affecting them. I'm assuming the black box on the other end is somehow able to read the original photons correctly?

However... What if someone were to have their own "black box", break the fiberoptic line, put one end into the receiver of their black box, and the other end out. That way you wouldn't be watching the photons go by, and affecting them. You could read them with your own black box, then re-transmit the correct photon.

Admittedly, this would be expensive, but if you are in dire need of reading something that had to be secured with quantum encryption, then money probably isn't of much concern.

Is this an incorrect assumption, or analysis on my part? I'm not a quantum physicist by any means, but I couldn't glean enough info from the articles to tell otherwise.

-Jesse

mo3 Down (-1, Offtopic)

Anonymous Coward | more than 10 years ago | (#8838030)

BSD machGines one Here but now moans 4nd groans

What is the use of this QC key exchange? (3, Interesting)

gay358 (770596) | more than 10 years ago | (#8838068)

As far as I know, this quantum "cryptography" prevents just passive evesdropping (where the parties are able to notice evesdropping because of this quantum "cryptography"), but as it doesn't include any kind of authentication, active attact (where all the messages are captured and the attacker is able to send his own messages) should be successfull. It is possible for Eve to just hijack all the messages and pretend to be Bob when communicating with Alice and to pretend to be Alice when communicating with Bob. It is of course possible to make this "cryptography" more secure by using some classical cryptographical methods, like authentication. But if we have rely to public key algorithms (which might become obsolete by advances in quantum computing), then it is not clear to me what is the advantage of using quantum cryptography in the first place. If somebody has answer to this question, I would be glad to hear it.

They will just make longer keys (0)

pyite69 (463042) | more than 10 years ago | (#8838069)

This will eventually be a problem for non-quantum algorithms, but if you need to protect against quantum decryption, then you can just use quantum ENcryption with extremely massive key sizes.

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>