Maybe the others here will have a better understanding what you mean by Hardware Security, but could you explain it to me?

Right now, all I can think is the physical hardware security of the systems. Things like limiting access; filling the device with epoxy to prevent parts being added, removed or modified; tamper evident labels on teh devices; etc.

This is the nearest thing I can think of.

http://www.devttys0.com/training/

The CISSP has a domain on Physical Security, but that is the only cert that I know of that does.

Beyond the defcon groups try to find a local lock sport group. those usually have people all about physical security in them. Somewhere else to look is Maker Spaces. they'll get physical with the hardware.

We will have hackable badges at B-Sides Orlando and a hardware hacking workshop http://bit.ly/BSidesORL /endshamelessplug