Daniel Gruss didn't sleep much the night he hacked his own computer and exposed a flaw in most of the chips made in the past two decades by hardware giant Intel Corp.

The 31-year-old information security researcher and post-doctoral fellow at Austria's Graz Technical University had just breached the inner sanctum of his computer's central processing unit and stolen secrets from it.

Until that moment, Gruss and colleagues Moritz Lipp and Michael Schwarz had thought such an attack on the processor's 'kernel' memory — which is meant to be inaccessible to users — was only theoretically possible.