[Southack]

"We could add a little thermite and intrustion detection on the chip, encased in an opaque epoxy resin brick, just to be sure."

Nice!

OK, that would do away with the laser drill...but now they'd use progressive acid drips to get to target depth.

[HAL9000]

I'd be surprised if the box didn't have some sort of self-destruct mechanism. It could be triggered in the event of a crash or physical penetration of the case.