As tempted as I am to try to summarize this paper on cryptography from MIT and the National University of Ireland titled Brute force searching, the typical set and Guesswork by Ken Duffy, Mark Christiansen, Muriel Médard, and Flávio du Pin Calmon, I fear that I would probably make a hash of it and then I'd have to let all of you math wonks beat me up about it.
The bottom line of the paper is that:
... a computer turned loose to simply guess correlations between the encrypted and unencrypted versions of a file would make headway much faster than previously expected.
"It's still exponentially hard, but it's exponentially easier than we thought," Duffy says.
So, once again we see that what we were sure was secure is considerably less secure than we believed. That's really rather depressing. Moreover, given the explosion of processing power over the last few years including GPUs and custom silicon such as the Epiphany chip from Adapteva keeping stuff secret is going to be much less certain.