WASHINGTON — The National Security Agency has built a surveillance system capable of recording "100 percent" of a foreign country's telephone calls, enabling the agency to rewind and review conversations as long as a month after they take place, the Washington Post reported, citing people with direct knowledge of the effort and documents supplied by former contractor Edward Snowden.
A senior manager for the program compares it to a time machine — one that can replay the voices from any call without requiring that a person be identified in advance for surveillance.
The voice interception program, called MYSTIC, began in 2009. Its RETRO tool, short for "retrospective retrieval," and related projects reached full capacity against the first target nation in 2011. Planning documents two years later anticipated similar operations elsewhere.
In the initial deployment, collection systems are recording "every single" conversation nationwide, storing billions of them in a 30-day rolling buffer that clears the oldest calls as new ones arrive, the Post said, citing a classified summary.
The call buffer opens a door "into the past," the summary says, enabling users to "retrieve audio of interest that was not tasked at the time of the original call." Analysts listen to only a fraction of 1 percent of the calls, but the absolute numbers are high. Each month, they send millions of voice clippings, or "cuts," for processing and long-term storage.
At the request of U.S. officials, the Post is withholding details that could be used to identify the country where the system is being employed or other countries where its use was envisioned.
No other NSA program disclosed to date has swallowed a nation's telephone network whole. Outside experts have sometimes described that prospect as disquieting but remote, with notable implications for a growing debate over the NSA's practice of "bulk collection" abroad.
Bulk methods capture massive data flows "without the use of discriminants," as President Barack Obama put it in January. By design, they vacuum up all the data they touch — meaning that most of the conversations collected by RETRO would be irrelevant to U.S. national security interests.
In the view of U.S. officials, however, the capability is highly valuable.
In a statement, Caitlin Hayden, spokeswoman for the National Security Council, declined to comment on "specific alleged intelligence activities." Speaking generally, she said "new or emerging threats" are "often hidden within the large and complex system of modern global communications, and the United States must consequently collect signals intelligence in bulk in certain circumstances in order to identify these threats."
NSA spokeswoman Vanee Vines, in an e-mailed statement, said that "continuous and selective reporting of specific techniques and tools used for legitimate U.S. foreign intelligence activities is highly detrimental to the national security of the United States and of our allies, and places at risk those we are sworn to protect."
Some of the documents provided by Snowden suggest that high-volume eavesdropping may soon be extended to other countries, if it has not been already. The RETRO tool was built three years ago as a "unique one-off capability," but last year's secret intelligence budget named five more countries for which the MYSTIC program provides "comprehensive metadata access and content," with a sixth expected to be in place by last October.
Ubiquitous voice surveillance, even overseas, pulls in a great deal of content from Americans who telephone, visit and work in the target country. It may also be seen as inconsistent with Obama's Jan. 17 pledge "that the United States is not spying on ordinary people who don't threaten our national security," regardless of nationality, "and that we take their privacy concerns into account."
In a presidential policy directive, Obama instructed the NSA and other agencies that bulk acquisition may be used only to gather intelligence on one of six specified threats, including nuclear proliferation and terrorism. The directive, however, also noted that limits on bulk collection "do not apply to signals intelligence data that is temporarily acquired to facilitate targeted collection."
The emblem of the MYSTIC program depicts a cartoon wizard with a telephone-headed staff. Among the agency's bulk collection programs disclosed over the past year, its focus on the spoken word is unique. Most of the programs have involved the bulk collection of either metadata — which does not include content — or text, such as e-mail address books.
Christopher Soghoian, the principal technologist for the American Civil Liberties Union, said history suggests that "over the next couple of years they will expand to more countries, retain data longer and expand the secondary uses."
Spokesmen for the NSA and national intelligence director James R. Clapper Jr. declined to confirm or deny expansion plans or discuss the criteria for any change.