US Senator Ron Wyden asked the new NSA boss - General Mike Rogers - at a Senate Intelligence Committee hearing today:
As a general matter, is it correct that anytime there are copies of an encryption key — and they exist in multiple places — that also creates more opportunities for malicious actors or foreign hackers to get access to the keys?”
NSA chief Rogers replied:
[It] depends on the circumstances, but if you want to paint it very broadly like that for a yes and no, then I would probably say yes.
Here's the exchange [2].