The NSA devised a system called RETRO that can search through all voice calls in a country over the preceding month, according to the latest revelation to come out of the Snowden leaks.
On Tuesday the Washington Post provided a rather light description of RETRO’s capabilities, avoiding any identifying reference to the country that was first targeted – and the 6 others that were apparently on the NSA’s to-do list – at the request of U.S. officials.
RETRO apparently began operations in 2009 and hit full capacity in the first target nation in 2011. It’s part of a program called MYSTIC (see logo above) and in the case of the initial target it works alongside a collection scheme called SCALAWAG, which somehow records all calls in the country. These calls are archived for 30 days, during which time they can be retroactively searched. So if a target is identified at some point, analysts can rewind and listen through their voice calls for the previous month.
Only a small fraction of the calls get listened to by analysts, but the documents show that early experiences with SCALAWAG nonetheless overwhelmed the NSA’s bandwidth and caused latency issues. This is clearly a lot of data to be dealing with – much more than metadata, which simply describes content (rather than being content) – though it’s hard to get a true sense of scale without knowing which countries we’re talking about.
The biggest hint in that regard is a reference to unnamed U.S. officials admitting that “large numbers of conversations involving Americans would be gathered from the country where RETRO operates.” Being bulk collection, of course, there’s no filtering out of calls involving people from specific countries, the U.S. included.
This is a pretty big story, as few thought the NSA had the capability to record such quantities of audio in bulk. Hopefully we will find out how and where it does this, because right now neither of those things is clear.