First of all. It is a pure fantasy, an entirely unrealistic wish of the Pink Unicorn variety that it is possible to create a key which only the US goverment (and other sanctioned agencies) would have access to. It is technically not possible. Ever. I explained that before so let me now just quote Bruce Schneier:
"We have one infrastructure. We can't choose a world where the US gets to spy and the Chinese don't. We get to choose a world where everyone can spy, or a world where no one can spy. We can be secure from everyone, or vulnerable to anyone. And I'm tired of us choosing surveillance over security."And let's be clear - we've been over this, the Clinton government wanted a similar thing with the Clipper chip and as security researcher Matthew Green pointed out:
Clipper is only one of several examples of 'government access' mechanisms that failed and blew back on us catastrophically.A second issue with the proposal is that it doesn't do anything. Just like all the spying programs that came before in this and previous decade. Here's Bruce talking about that, here the Guardian, the Newyorker, Wired and Washingtonsblog. Whatever these spy programs do - from spying on German Chancellor Merkel to US congress (that's the Washington Post itself!) to the United Nations and Unicef - the government spying programs certainly don't target or are helpful against terrorism or pedophilia or any of the other stuff they are claimed to be for. And neither will these 'golden keys' be used to catch terrorists.
Last, and this should already be blindingly clear if you see the list above of some of the targets of surveillance, you should doubt if the government agencies will abide by the rules - they haven't in the past.
I also want to point out that the very reason we're having this conversation in the first place is because we're idiots.