http://www.cc.gatech.edu/grads/c/csong43/oakland16-hdfi.pdf
Its related work & extension page has a ton of references to other things showing just how much work it is to stop regular black hats in systems without verified software. Nation states just do more of the same stuff.
Edmison's has a nice survey & design for when you don't trust anything outside the SOC:
https://theses.lib.vt.edu/theses/available/etd-10112006-2048...
NSA targets those levels, too. At that point, your bases are covered so long as the fab receives and doesn't alter your design. Plus the complex tooling works...
Edit, it seems I have copied the wrong video, please us the link in the child comment
Why would the NSA eavesdrop on Google, they are in bed with them, aren't they?
Of course they can still use courts to get data directly from Google, but that way they can always only target individuals or small groups, not whole nations.
[1] http://www.huffingtonpost.com/2014/05/06/nsa-google_n_527343...
Because at the time Google did not use encryption in their network links between data centers, NSA was able to siphon up a whole lot of information that way - maybe more than just interaction between users and Google services, potentially as much as interaction between internal components of Google.
Anyway, Google and other companies responded by employing encryption in these links, and promoting the use of encryption across a number of other protocols. The Snowden disclosures were in my perspective a catalyst for Google's promotion of HTTPS in the Chrome browser, and TLS in Gmail, and probably Certificate Transparency. The fact that these initiatives such as encryption between data centers started after the disclosures suggests that they were a response from Google to thwart this kind of surveillance.
Personally I would go further, those multi billion dollar companies should have found a way to speak up if a contractor was able to, not just after the fact.
[1] https://en.wikipedia.org/wiki/PRISM_%28surveillance_program%...
https://www.washingtonpost.com/world/national-security/nsa-i...
First, they can force Google to hand over anything. NSLs and the PRISM program are evidence of this, and both are relatively narrow in scope. However, each time the feds compel a top-tier tech corporation like Google to cooperate, the entire thing is scrutinized by lawyers on both sides, and risks drawing the ire of pissed off employees. There's probably many more potential Mark Kleins in Google than there are at a telecom like AT&T—the latter company's relationship with the NSA being best categorized as incestuous.
That being the case, why conduct bulk data collection overtly when they can do it covertly? The aforementioned overt measures ensure prompt data access in the event of an emergency, and keep everyone thinking they're on the up and up. Meanwhile, the truly nasty stuff like domestic bulk collection is conducted behind the scenes.
I don't know. Maybe it is easier than going to court all the time? Who knows?