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Negative Databases
How can you NOT like an article that begins like this?
IN THE 1940s a philosopher called Carl Hempel showed that by manipulating the logical statement "all ravens are black", you could derive the equivalent "all non-black objects are non-ravens". Such topsy-turvy transformations might seem reason enough to keep philosophers locked up safely on university campuses, where they cannot do too much damage. However, a number of computer scientists, led by Fernando Esponda of Yale University, are taking Hempel's notion as the germ of an eminently practical scheme. They are applying such negative representations to the problem of protecting sensitive data. The idea is to create a negative database. Instead of containing the information of interest, such a database would contain everything except that information.
So this should be easy enough to test. Hook a client up to the database, and if it tells you something you didn't want to know, must be working.
I love computers. We get paid for this! Here is some more:
Dr Esponda sees great potential for using negative databases when there is a need to look at the intersection of many sets of data owned by different parties. Two or more banks, for example, might wish to work out which transactions they have in common without revealing the whole contents of their databases. Using negative databases to do this would, according to Dr Esponda, provide a robust back-up to traditional cryptography, which relies on codes that can be broken.An interesting extension of the idea might be to use negative surveys to collect sensitive information privately. Dr Esponda gives the example of a negative survey in which respondents are asked to tick the box of one sexually transmitted disease they do not have. He reckons that this would be sufficient to estimate the population frequency of each disease, without having to ask people whether they actually suffer from such diseases -- which is intrusive and also invites lying. As he puts it: "In Hindu philosophy, to find out who you are, you ask what are you not. Then you are left with what you are."
This opens up a whole new world for web developers. Instead of a login screen where you tell the server who you are, maybe you should just tell it who you aren't. Want information from your checking account? Too bad! We'll give you information from another checking account -- you can go and reconcile that guy's account for the last month. Want to go traveling? Where would you NOT like to go to? We probably can't hook you up. I'd like to read some blogs today, but the computer always keeps track of where I am not browsing and takes me there.
Now that we have negative databases, I wonder when the negative applications will come along? Tell me what you want the application to do, and I can guarantee it won't do that.
Ahh. Philosophers and computers. Life is good.
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AGGGHHHH this post makes my head hurt! Just like all philosophers!