Using Diamonds to Create Unhackable Code

IAmTheDave writes "Researchers at Melbourne University have grown diamond particles 1/1000 of a millimetre on optical fibres which they can use to transmit single photons of light at a time. The diamonds are grown on the optical fiber by raining carbon molecules onto the tip of the fiber. They claim that by transmitting information in single photons, any interception of transmitted photons will be useless to the interceptor, and thus the message will be completely unhackable. Transmission speeds are currently slow - 120km/h, but are expected to speed up."

Comments

That's unhackable TRANSMISSIONS, not code

[Chas]

Jeeze.

Re:That's unhackable TRANSMISSIONS, not code

[nametaken]

In light of the fact that we just found the "biggest compromise in history" of secure data was perpetrated by idiot employees selling peoples profiles for $10 (USD) a pop, I'm less worried about unhackable transmissions and more worried about the people at each end.

Lets remember to call our banks.

Now for my master plan...

[Bananatree3]

Stretch 3000 miles of this across the atlantic, set up a secret recieving station on the African coast, and voila! One secret, untappable method for my world takeover, I mean, world communication plan!

"Unhackable Code"?

[cbrocious]

This is far from an "unhackable code". In fact, it's not even a code. Please stop thinking that "quantum cryptography" is a form of cryptography. It's simply an interception-resistant media.

Re:"Unhackable Code"?

[hotspotbloc]

Exactly. When it's too tough to crack the technology then it's time to use social engineering or a key capture hardware device built into a keyboard.

There is nothing unhackable.

Re:"Unhackable Code"?

[cbrocious]

Speaking from the standpoint of someone who does a lot of reverse-engineering (PyMusique/pyTunes was my baby) I'd say that 99% of the time, neither of those methods are neccesary. Usually you can get what you need from either the source or destination directly. Most people seem to overestimate security in computer systems. I just can't wait for "quantum cryptography" to be used for DRM keys so we can have a bit of fun ;)

Re:"Unhackable Code"?

[Kainaw]

Please stop thinking that "quantum cryptography" is a form of cryptography.

That depends completely on how it is used. If I simply send a message in 1s and 0s over the photon stream, it isn't encrypted. I can only be certain that it either got there or it didn't get there.

Cryptography comes in when you encode a message using a photon stream. The mechanics of doing this are old hat by now. It is done in the following steps:

1. Send a stream of, say, 2,000 random 1s and 0s to the other end.
   
2. The other end pics, at random, 500 of the 1s and 0s and sends a plain message back saying only which are chosen - the index, not the value. So, you can both form a 500 bit key (the number of bits is to your choosing)
   
3. Encrypt the message using the key you just worked up and send it.
   

This is commonly said to be 'mostly secure' because it is vulnerable to a man-in-the-middle attack. However, it is tamper-proof once it begins. If anyone attempts to read any of the photons as they travel down the stream, they alter the photons. So, you get a scrambled message at the other end and the hack is immediately known.

Because it cannot be copied enroute without giving away that it is being copied, it is commonly called unhackable. You cannot make a copy of it and send it along while you try and hack it. I know, you are thinking you can just copy the photons and resend new ones with the same message. Nope - you have to know the spin orientation of the photons BEFORE you can read them for a 1 or a 0. If you read it with the wrong spin orientation, you will force it to the orientation you read it as and get an errant 1 or 0 that you incorrectly send down the line. So, you could say it is doubly-encrypted and doubly-protected from in-line hacking.

Re:"Unhackable Code"?

[xiphoris]

Mod parent and grandparent down. Quantum Cryptography is indeed real cryptography. It uses the encryption system known as the One Time Pad. The "Quantum" aspect of it is used in transmission (really, creation) of the random pad on both sides of the communications line.

There is nothing unhackable.

Perhaps, but information encrypted with quantum cryptography is un-interceptable. Because of the way a one time pad works, you have no way to verify that you've cracked a message -- any "decrypted" result is the same as any other.

This is distinct from other encryption methods, which use complicated math to encrypt and decrypt things.

A one-time pad is merely a block of random data. You XOR your pad with your plaintext to get ciphertext. With a given ciphertext block, you have no way to verify what the correct plaintext is. For example, if I have a ciphertext message: ABCD, that could just as equally be the plaintext HELO as ROFL.

Quantum cryptography is the usage of quantum mechanisms to generate the same random data at two different locations. Because of properties of quantum physics that I don't personally understand, interception of that quantum data is impossible.

But no, quantum cryptography is not breakable because it's impossible to know whether you have the correct plaintext, and it's impossible to get the one-time pad from the quantum transmission line (physics guarantees it). In other encryption systems, you know mathematically whether you have discovered the "key". The ciphertext of a one-time-pad, according to information theory (and the assumption that your pad is made of truly random data), provides you absolutely no information about the pad or the plaintext.

See more here: http://en.wikipedia.org/wiki/Quantum_cryptography

Re:"Unhackable Code"?

[eddeye]

Quantum Cryptography is indeed real cryptography. It uses the encryption system known as the One Time Pad.

Not long ago, I took a graduate course in quantum computing from a researcher in the field. I wrote a paper for that class specifically on quantum cryptography. In 2001, I worked in the same lab as a physicist building a quantum cryptography device (we had lunch almost every day). I've also studied quite a bit of conventional cryptography. Trust me when I say this:

Quantum cryptography has nothing to do with encryption, and barely anything to do with cryptography. It's an authentic channel with eavesdropping detection (but not prevention). In other words, QC is just a bootstrapping phase to distribute key material (random data) to two parties. Everything you do from that point forward, including everything involving your actual data, is classical crypto on classical channels.

QC has nothing to do with one-time pads. You could use the key material for OTPs, if you're deranged. More likely you'll use something like CBC-AES, CTR-AES, CBC-3DES for encryption, which are much faster (less key material, not limited by QC data rate), simpler, and safer (unless you have the resources of a major world government to oversee proper handling of the data and key material at every point from creation to destruction). At any rate, you'll still need integrity even with a OTP or your data is worthless. That means SHA1-HMAC, CBC-MAC-AES, etc.

Cryptography proper punts on the key distribution issue as it's not solvable mathematically. It's an administrative not an algorithmic problem, putting it outside the domain of modern cryptography. This applies equally to asymmetric crypto; public key databases and root certificates require proper oversight and maintenance. Hence the one problem QC solves, key distribution, is really external (but related) to the field of cryptography. That's why I say the two are orthogonal.

The funny part is, QC isn't even a good solution to key distribution. Its physical requirements are costly, stringent, and limiting. Unless you're an ultra-cautious damn-the-expense client like the US govt, there are more cost effective ways to exchange keys, and much better ways to improve your data's security. QC is a problem in search of a solution.

Curious

[Anonymous Coward]

I'm left wondering how it is they've managed to slow down the transmission of a photon to 120 kilometers in one hour, presumably in the glass fiber. Usually slowing down light that much takes a great deal of infrastructure and effort, it's rarely a side-effect.

Slashdot and the www.news.com.au couldn't have both made the same screamingly stupid mistake and meant 120 kilobits per hour, right? Right?

Unhackable... Unnecessary!

[WaR.KiN]

It's not that the code is unhackable, it's just that hackers won't be hacking into your bank account anymore. They'll just take the diamonds.