I was looking for a study I read a while ago on a popular cryptographic discussion: key length.  As Bruce Schneier points out this is a real problem.

I remember this mathematical article was hard to find; so, I was all set to spend 30 minutes googling for it.  Then I had the bright idea of searching for key length and I found a great site on it:

http://www.keylength.com/

This site points to the study I read and updates to it since.