Uncrackable network

[d0ppy]

Soon we shall see.... Ettercap, Quantum Edition.... with photon injection....


Offense will catch up to defense.


That's how the game is played.


And it's not unhackable. It just has to be hacked in a different way at the moment

[Neverness]

Agreed d0ppy, I believe it is better to be a skeptic than to attempt to defend a system that has not yet been fully exposed to appropriate analysis, whatever that may be. Granted, I am a layman when it comes to quantum physics (which I would guess everyone else here is as well), yet I see this as a challenge instead of a end-all solution. Exciting as this is, I feel more secure assuming that this system has exploitable flaws than assuming it can never be hacked. The denial of service idea preventing communication was really funny, yet hopefully that wouldn't be a problem. All in all, very exciting prospect and thanks for finding the article.

[Tim_axe]

...
Simply sniff the communications channel, looking for nothing and storing nothing in particular (just be there) and the keys keep getting thrown away so the REAL communications never happen.
...

Ditto. I've been hinting at that over the last few threads on Quantum Key Distribution I've been in on AO, though nobody seemed to get my point.


Another thing that is important to note is that the whole point of this network is to (securely) distribute increasingly larger keys for standard encryption processes. The threat of a quantum computers searching huge keyspaces quickly has prompted a shift to prepare current networks to handle larger key-sizes that exponentally increase the keyspace. A quantum key distribution network looks to be quite secure, but soon bandwidth may need some work to represent larger keys that are more future-resistant against the possibility of a working & powerful quantum computer or some breakthrough in factoring.

This network has nothing to do with a new methodogy for encryption. It just gets larger keys from point A to point B reliably and securely, and is even supposed to allow you to notice when someone tries to intercept your network communications. (Although that last bit has me worried...with supposedly no redundancy, how can you possible error check? This looks like one part of the process that seems to contradict itself, though I may just not understand how the network actually operates, etc...)

Basically the larger the key, the more secure you theoretically are because there will eventually be a point where a given itteration of quantum computers couldn't search the entire keyspace fast enough (2^999999999999999 keyspace/key-size anyone? Up to 303,030,303,030,303 digits long, takes up 113.68TB of disk-space per key, 24,770 4.7gb DVDs...how is that for "takes a long time"?), so that it would be considered "secure", or at least more secure.

Well, after throwing out (and working out) that huge number in the example, I should probably dip into what a quantum key distribution network should solve. It should quite simply allow you to secretly transport your huge keys, and know when someone got ahold of a copy of them so you can generate a new key. (Although if you ended up missing 24,770 DVDs, I'd hope you might realize that key could be compromised and you'd better not encrypt your data with that key set) The key exchange is supposedly worked out before hand, so that once the two nodes have agreed on a key, the information will be encrypted with that key and then sent over public channels...


<fragment>I've also been researching into Man-in-the-Middle attacks and how they would have to operate to play a Quantum network. Conventional encryption/authentication schemes and not some new fabled quantum-crypto stuff, actually make it somewhat difficult to do a man-in-the-middle attact. Mainly since as the man in the middle, you must make sure to negotiate keys to something you can decrypt and encrypt between parties, but also make sure that Alice and Bob don't somehow know / figure out what each other's key *should* be through their communications and eventually realize that there is a man in the middle logging everything and re-encrypting it on the route from Bob to Alice, etc. Either way this process should be difficult given how there are two seperate channels to monitor (public internet & the quantum key distribution network) and that Alice might actually meet Bob in person (or perhaps even the man in the middle meets Alice/Bob) to exchange the keys. If it goes wrong, Alice or Bob may realize the negotiation isn't what it should be, etc., and then refuse to send the key...</fragment>

[MoonWolf]

A foolish idea that popped up in my head and could possibly be very inpractile.

I think that using quantum entanglement you could change the state of one atom by changing the state of a second atom.

I have no idea how distance affects this. But if distance does not matter much, there you have the most secure channel ever.

[Und3ertak3r]

I will need to read a hell of a lot more on this subject..

When two photons are created, there exists the potential for an opening to an eavesdropper. If a hacker can intercept just one photon key they have enough information to decrypt one bit of a message. "We don't like it when we get two photons," Yeh says.

but even if 50% of photons are twins.. you still only get half the message

Here is a point I was going to make.. Distance..Joins, Repeaters..

In addition, using single photons to build encryption keys has one fundamental drawback: distance. Optical networks need repeaters--which strengthen and advance signals--every 100 kilometers to keep their signals strong over long distances. But like the theoretical eavesdropper, a repeater has to observe the photon in order to amplify it and send it on, thereby ruining the key.

Hmmm gravity neutrinos, radiation? magnetic fields.. (I will read on)
But these things will affect a beam of photons..

[Aspman]

Schneier isn't a fan of quantum crypto

http://www.schneier.com/crypto-gram-0312.html#6

Quantum Cryptography
MagiQ Technologies is now selling an actual product that uses single photons to exchange keys over fiber optic lines. Navajo systems use photons to transmit encryption keys over fiber-optic lines, and the security is based on the quantum law that an observer--an eavesdropper in this case--perturbs the system by observing it.

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.

Security is a chain; it's as strong as the weakest link. Mathematical cryptography, as bad as it sometimes is, is the strongest link in most security chains. The computer security, the network security, the people security--these are all much worse.

Cryptography is the one area of security that we can get right. We know how to make that link strong. Maybe quantum cryptography can make that link stronger, but why would anyone bother? There are far more serious security problems to worry about, and it makes much more sense to spend money securing those.

It's like defending yourself against an approaching attacker by putting a huge stake in the ground. It's useless to argue about whether the stake should be fifty feet tall or a hundred feet tall, because the attacker is going to go around it. Even quantum cryptography doesn't "solve" all of cryptography: the keys are exchanged with photons, but a conventional mathematical algorithm takes over for the actual encryption.

I'm always in favor of security research, and I have enjoyed following the developments in quantum cryptography. But as a product, it has no future.

It's always the people that are the problem and they still have to be at either end using the system.

[foxyloxley]

but even if 50% of photons are twins.. you still only get half the message

My take is that you get the message duplicated / cloned ?

Here is a point I was going to make.. Distance..Joins, Repeaters..

There is, in the quantum world, wherein distance is NOT an issue, where something that happens here, can have an instantaneous effect ANYWHERE in the universe ..................

Schrodinger's cat is the basis :

Where Schrodinger whilst attempting to show the absurdity of the quantum theory, devised an experiment.

A cat is sealed into a container, in there is a phial of poison, and the trigger is a lump of radio-active material, it is possible to set up the experiment so that there is a 50-50 chance that ONE of the atoms will decay in a set time, and emit an electron, which would release the poison and kill the cat.

But, until it is OBSERVED, the cat is neither dead nor alive, but exists in both states at once.

Now, if you take a second cat / container / et al.
Now, ONE cat WILL be dead, and ONE will live.

The instant that you open one container to check on the cat, at that instant the fate of the other cat is known, and the distance to the other cat was irrelevant.

This is [obviously] just a rough hash of what I've perused in my reading.

Please don't ask for details, as the details just get weirder
In the crypto world it might not SEEm as thought there is any connection, but when it comes to Quantum; ANYTHING can happen..........

[ZT3000]

After that little lecture,

Beam me up Scotty!

[MichaelAZ]

Its imposible to create an un crackable network because there is always the human element nothing that is done by a human is ever perfect only god can create something that is truly perfect. There will always be a student to show up the master so to speak. someone will write done a password or put it on their pda of something then some one will hack the pda and get the pass and their in. and dont even think of neging me for being stupid cuz im not if the pda belongs to someone with access to the system then the pda becomes a part of the system and it can be hacked