Ultrasecure Quantum Communications Over Thin Air

SlashDotIDOne writes "Well, given a hundred years at university and a few extra titles to my name, I'd be comfortable trying to summarize the article so don't take what I say at face value. Apparently British and German researchers have found a way to use quantum crypto through the air, thus allowing it to be used to communicate with satellites, etc. A very secure form since you know whether a message was intercepted, rather hard to tamper with ;). Courtesy India times and Google's new news service."

Comments

Allowance of crypto

[explosionhead]

The big question, though, is whether they should be allowed to enter the commercial domain, where they could be used by organised crime and terrorism to thwart eavesdropping by police.
Whether they should be allowed?? Whether they're allowed or not has little bearing on what would happen. You look at the US's export restrictions for crypto, asking people outside the US to download the inferior version, they haven't exactly worked wonders have they?

Re:Allowance of crypto

[JonnyCalcutta]

The big question, though, is whether they should be allowed to enter the commercial domain, where they could be used by organised crime and terrorism to thwart eavesdropping by police.

Yes, this was the bit that got me as well. It amazes me that this sort of thing can be stuck in as a throw away sentence, as if to imply that there is no doubt about the correctness of this POV, and anyone who thinks otherwise must be stupid.

The saddest thing about the world we live in (in the West at least) is the horrible kneejerk 'won't somebody think of the children' attitude that comes before any form of rational thought is employed.

Here's my list of things we must ban immediately -
Let's ban pencils, pens and paper, since criminals can use them to draw plans of the joint they are casing or even, God forbid, create one time pads to pass uncrackable codes to each other.
Ban open spaces since criminals could use them to converse with each other out of earshot of the police.
Let's ban flags since they could be used to pass secret messages in semaphore.
In fact let's just ban all forms of verbal and non-verbal communication - let's see those criminals make plans now!

Slashdot would be the first to go obviously. All that 'geek talk' is obviously just a clever criminal code.

In some ways it's solving the wrong problem

[WolfWithoutAClause]

The easiest way to crack encyption is to avoid cracking the encryption and attack the installation or the people using the encryption.

Basically, if you can bug the users keystrokes when they type in their password for the crypto system, then that system is toast- similarly if they have a physical token- if you steal that token.

Or you bribe/blackmail the guy; or you use "lead pipe" cryptanalysis- you hit the guy over the head until he tells you his password.

This system looks good; but don't assume that its going to be 100% secure. In the real world it can't be, unless there's no people in the loop, not even designing the system.

Re:Setting the Agenda

[fruey]

Who said that this is the big question? This is not the "big question"; it has already been determined that "terrorists" did not and generally dont use crypto for communication, so thats just a lame excuse to keep the tools crippled (see A5).

Exactly. Indeed, the real criminals (corrupt bankers, high wealth people, etc) are those that use crypto because they have the money and paranoia sufficient. Terrorists use simple stuff like codes, languages that only the top spies can get translated, and other tactics like human silence policies and any number of other things. As for organised crime, well using PGP / crypto etc is just going to get the FBI to prick up their ears a bit more so is generally avoided.

People should not be paranoid about cryptography, it should be openly available. It should be used primarily for signatures, and yet most people just think it's there for protecting data transmissions. *Sigh*

Philip K Dick

[pubjames]

I remember reading once that Philip K Dick (writer of Blade Runner, Minority Report) went mad at the end of his life, one of the reasons being that he was convinced that there were zillions of alien transmissions going through the air which were screwing with his mind.

Perhaps he was right. Perhaps taking lots of hard drugs allows you to tune in to alien quantum communications. Sounds like some experimenting needs to be done...

Re:Any details at all would have been nice

[stevelinton]

I had a student do a project on this. You can live with quite high levels of photon loss.

Essentially, the process runs:

send a large number of (more-or-less) single photon pulses, carrying random data

recipient reports over an open channel, which pulses they got and some more technical information.

From this, sender and recipient can work out the subset of the random data that they take into the next step.

Now they (openly) exchange some checksums and things to determine the rate of bits which appear to have changed in transit, either due to eavesdropping, or noise and to get a common bitstring. From this, they can work out how to combine the bits of the bitstring to get a shorter bitstring which (with high probability) no eavesdropper can guess any part of.

Finally, they use this common secret bitstring as a key for a one-time pad.

Simulations suggest that even 99.9% photon loss is not fatal.

Speaking of Google's New News Service...

[Uttles]

Does anyone else think it would be a great addition to Slashdot's stories if they would include a link to the google news search under every headline? I don't think it would be that hard to automate, but it sure would open the door for us users to see a lot of different articles per issue discussed.