Thursday, June 26, 2008

Jazoon Cut: Privacy Supporting Identity Systems

Jazoon Cut is a nice idea: You got a project, they give you 20 minutes to present it (i.e. "cut" as in "cutting edge"). In this Cut, we had NetKernel, iGesture, Interactive Paper, and Privacy Supporting Identity Systems. A rather interesting mix.

When we buy something, we hand over money. This money is untraceable. If the vendor passes it on to his bank later, there is no way anyone could tell that it was you gave him this specific bank note or what you bought with it (the vendor might know that but again, he couldn't say which bank note you gave him). This is a good thing. If the bank could figure out what you bought, some people would become very interested in this data, for example marketing people. They are looking for a way to measure how easy we are to influence for ages.

But the area is getting more tight. If you had some RFID chips on you, say, one of those new passports or a contactless credit card, I could place some people in a shopping mall or city center with technology to track where you go. Under optimal conditions, an RFID chip can be tracked over the distance of 60 meters. That's not much and I probably need a couple of radio stations spread over the city to do that but with such a system, I could find out what you buy.

"Now," you say, "I can't be identified by that," and you'd be wrong. Some credit cards will offer all the details stored on them (enough to buy something with that data in the Internet) when asked. For the rest of you, you're lucky until someone figures a way out to do that. Nonetheless, even if I don't know your identity I can track you. So if your last stop was at an expensive jeweler, chances are that you have enough money that it's worthwhile to mug you.

And I can pick you from a safe distance of 20 to 60 meters, follow you around out of sight and wait for the perfect moment to strike. Oh, and better not step into some sex shop because I'd know. In fact, I can track your movements for a couple of days, find out where you live (and thus your identity). All without you ever knowing that I even exist.

I hope I have made you understand that the question is not that you have nothing to hide (which is not true; when was the last time you filed a correct tax declaration?), the question is what evil someone could come up with if he knew something about you. The problem with this question is: Nobody knows the answer until someone comes up with a new evil that nobody else thought about so far!

In his talk, Thomas Heydt-Benjamin showed how you might be able to have both: Comfort and security. The attack described above wouldn't work if the range of the RFID chip in your credit card would be reduced to a few centimeters. It would still be comfortable if you had to put it on the desk for a moment, making hard contact with the surface to be able to read it. Surely, you would notice if someone followed you holding a strange device to your pocket.

The next thing is the data on the card. The vendor needs the data to know who you are and if your credit is valid. But actually, he does never have to see the real data. The only thing he needs to know is "credit is valid" or not. He doesn't need your credit card number. Or the name. Or the expiration date. Or the security code on the back. What could be done is this:

You check into a hotel. You present your passport to the reader device on the desk. On your side of the screen, you can select which data the hotel guy can see. To allow the police to track you in case you didn't pay your bill or you're involved in some kind of crime, the hotel's computer gets an encrypted code that identifies you. For everyone who can't decrypt this key, it's just a long, random string of data. For all legal means and purposes, you're as anonymous as you want. While this might not make much sense in the hotel scenario (hotel staff hates it to call everyone "Mr. Smith"), it starts to make sense on the Internet.

You're stuck in some kind of game and want to check the walk through. Only, the game is for people over 16. So the site with the solution should check your age because the walk through contains all those images which were the reason for the age limitation. In this case, you only want to tell the site your age or rather that you're older than 16 and nothing else. You don't want to tell them your name, or where you live. Otherwise, the police might decide to shoot you for reasons of precaution (this is an example, okay?).

Or let's face the truth: 99% of the Internet is pr0n. And you surely don't want to leave your personal details with people who treat women like in the movies they sell.

With the Higgins framework, such things are possible. This framework allows to transfer data like "I'm older than 18" in such a way that the other side can be sure you are even though they will never find out what your real age is or your name. At the same time, it doesn't allow for illegal activity because you can be identified by your IP address and when the police compares the data sent to the web site in question and your passport, they can prove without doubt that it was your passport that was used in the transaction.

At that time, you want a passport that can't be skimmed in the subway.

While I talked to Mr. Heydt-Benjamin, he also explained to me that certain pacemakers contain a radio interface. Which makes sense. By this interface, you can query for the patient's data (name, for example) and you can also control the pacemaker. This interface is not protected by any encryption or password. So you can see the heart curves recorded by the sensors. But you can also change the sensor settings of the pacemaker. This is actually what happens when the doctors adjust them to your needs after the surgery.

The scary part is that the pacemaker has a function to stop a heart. This is necessary to "heal" certain kinds of heart rhythm irregularities like ventricular fibrillation. Now if I'm a hacker and I don't like you, I can turn off the sensors and stop your heart. The device will try to start your heart again after stopping it but that will fail because the settings of the sensors will prevent it to get any feedback.

So if you can see a large antenna at the horizon, the words "denial of service attack" might make you feel a little bit uneasy in the future if you do need a pacemaker.

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