Comment Links to Articles (Score 1) 266
The problem is not that it is impossible, just that most current implementations are extremely slow. Song implemented ranged query over encrypted data on gMail and even with encryption accelerators the performance was low.
Some more papers:
http://www.springerlink.com/index/370086k273w1587t.pdf
http://www.cs.berkeley.edu/~dawnsong/papers/rangequery-full.pdf
http://www.springerlink.com/index/u2007h5706482j51.pdf
There have also been some different multi-server database schemes that do the same thing, although, once again, due to performance and the cost of maintenance I do not know of any that have actually gone to market
Hope those help. Hit me up if you want more info.
-Nav