Ask HN: What are some network security/IA topics you'd like to see researched?

Like the subject says.

Background: I have an opportunity to do some post-grad research in the near future and am having trouble finding something still unexplored.

I'd originally wanted to look at encrypted protocols which end up revealing (through metadata, etc.) what's really happening. However, I see a lot of work has already been done in that arena.

So, I'm turning to the collective wisdom of HN for ideas on where to focus my efforts. I'd prefer something IA- & network- related, but would gladly consider anything.

Thanks!