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Code for Unbreakable Quantum Encryption
An anonymous reader writes "ITO is running a story on NIST's latest quantum encryption key generation. From the article: 'Raw code for "unbreakable" quantum encryption has been generated at record speed over optical fiber at NIST. The work is a step toward using conventional high-speed networks such as broadband Internet and local-area networks to transmit ultra-secure video for applications such as surveillance.'"
Sorry, but this *is* unbreakable.
This is no logic which can be broken by brute force of amazing insight.
This is the basic law of physics at work i.e. the quantum state of a pair have information which stays the same even if they are far apart. (I think they are using this one here).
One changes, the other knows. So somebody peeks to it, they guy knows it has been peeked into.
So, looks like this is it.
rajmohan_h@yahoo.com
People really need to quit referring to anything as "unbreakable" or 100% secure.
Well a one time pad is considered unbreakable if employed correctly.
However, if you reuse the same pad over again and over again it tends to be easier to break. Maybe that is why they call it a one time pad though...
"I am the king of the Romans, and am superior to rules of grammar!"
-Sigismund, Holy Roman Emperor (1368-1437)
Nice bit of text going over the key exchange. Dosn't even involve hurting cats.
"Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
Well, if you use one time pads, they are unbreakable (if they are generated using a truly random feed). The problem is getting the to the destination securely. If you use quantum encryption to transmit the one time pads, you can detect wether one has been intercepted or not. If it has, discard it, if it hasn't keep it and use it.
Google for one time encryption pads to get a better idea of how they work.
The article is about quantum encryption, not computing. IIRC, quantum encryption employs the quantum characteristics of photons to make it impossible to eavesdrop on a communication without altering it, thus rendering it uncrackable. Whereas quantum computing employs the overlapping of quantum states of systems in order to provide a kind of natural ability to perform "parallel" computations.
If it weren't for deadlines, nothing would be late.
All together now: "this has nothing to do with quantum computing".
This system exploits quantum mechanics to detect if someone is interecepting and retransmitting the signal. That's why it's called Quantum KEY Distribution. There's nothing "quantum" about the encryption itself. It is also of limited use since it requires an unbroken fiber-optic connection between the two devices.
The idea of quantum cryptography is that you have some form of signal sent both ways that only the receivers can receive, since it can't be tapped in the middle due to detected signal loss and single-atomic-unit transmissions being measured. It's pointless, because anything the actual receiver can do, I can do too, and anything the actual receiver can't do I can't do either.
Eeeehh... Quantum entaglment encryption isn't that simple.
Here is a site by Colossalstorage that explains one of the patents involved in it:
http://colossalstorage.net/entangled.htm
To give a layman's translation... You take two photons and entagle them and then send them down two fiber optic line of the same length (say 4km) and then a device on each end determines which direction the spin is.
Since the spin is the same for the particles regardless of how far apart they are (no information being transfered faster than the speed of light) they have a reference of what the other party is seeing.
Now of course particle spin is random, but the key factor is knowing what the other party is seeing.
Now, you can use the spin as a one time pad and basically encrypt everything based off this... Or rather changes are you'll need another method of communication such as having the actual encrypted data on another fiber line and knowing the spin of the photon gives you the key to unencrypt it.
Now if someone spliced the fiber line, you instantly know it has been comprised because data no longer unencrypts because the particle spin changed on observation and chances are unless the eves dropper has the ability to observe particle spin he might not get much useful data either.
"I am the king of the Romans, and am superior to rules of grammar!"
-Sigismund, Holy Roman Emperor (1368-1437)
The one big vulnerability with OTPs is that you've now got to send the key securely. Since it is equal in size to the message and is only valid for one message, it is equally hard to send the key securely as it is to send the message securely. Because the pad is pure randomness, it is possible (using existing methods) to send the pad by public key encryption, as it is non-trivial for someone intercepting the message to know how to decrypt it, as it's hard to know when you've broken the encryption. One piece of randomness looks much like another.
Generally, though, people take shortcuts. Instead of using a full-sized one-time pad, a much smaller, repeatedly-used pad is used instead, with some form of pseudo-random mangling to churn things up so that it acts in a very similar manner to a one-time pad. This is generally how stream ciphers work.
Quantum Cryptography - if used sensibly - would involve transmitting a gigantic OTP. Far bigger than the one you need. You then drop all of the bytes that are intercepted. The only bytes used in the pad are the ones the intercepting person does NOT have, so you know the pad is free of holes.
A "better" solution would be to not transmit the key at all, but somehow exploit photon teleportation to deliver the key in a secure manner. However, if you could do that, you wouldn't need encryption in the first place.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Yes, it is two separate issues, but they work together.
You use the quantum technique to transmit the key and are sure no one intercepted it. You then use that key which no one else knows as a one time pad to encrypt your data. One time pads are mathematically proven to be unbreakable.
"From my cold, dead hands you damn, dirty apes!" - CH
Its not encryption, but is what is called a hash. Think of it more like a fingerprint of data. If you alter the data then the fingerprint is no longer the same.
/. thread is 2 way encryption, meaning you would determine the original data from the encrypted data.
Now a hash is what would be called one-way encryption. That means from the 'encrypted data' there is _no way whatsoever_ to determine what the original data was. What is being discussed in this
The md5 hash is useful if you want to verify a password without sending the password itself across the line, you can just compare hashes without fear that someone is going to intercept the password itself. It is been proven that 2 datasets can produce the same md5 hash (this is known as a collision). This is why you have run into md5 being used in conjunction with passwords. That being said, as it is a one way encryption, md5 would be of no use whatsoever if you were trying to securely transmit a file, it would only be useful for the person on the other end to determine if the file had been altered in-route.
Hope that helps.