Between NSA's Bluffdale, Utah data center, the government's supercomputer facility in Oakridge, Tenn., and possible cracked primes, backdoors may be unnecessary.
James Bamford's 2012 WIRED article The NSA Is Building the Country's Biggest Spy Center (Watch What You Say) is a fascinating read about the NSA's monster data center near Bluffdale, Utah and what it might be used for. Here's an excerpt:
"Breaking into those complex mathematical shells like the AES is one of the key reasons for the construction going on in Bluffdale," explains Bamford. "That kind of cryptanalysis requires two major ingredients: super-fast computers to conduct brute-force attacks on encrypted messages and a massive number of those messages for the computers to analyze. The more messages from a given target, the more likely it is for the computers to detect telltale patterns, and Bluffdale will be able to hold a great many messages."
Bamford then suggests the super-fast computers are part of the High Productivity Computing Systems program located in Oakridge, Tenn. (of Manhattan Project fame), specifically in Building 5300 according to a former senior intelligence official involved in the project interviewed by Bamford.
The official mentions that security intensified in a big way when the Building 5300 team made a huge breakthrough, adding, "They were thinking that this computing breakthrough was going to give them the ability to crack current public encryption."