WASHINGTON – The National Security Agency has secretly broken into the main communications links that connect Yahoo and Google data centers around the world, according to documents obtained from former NSA contractor Edward J. Snowden and interviews with knowledgeable officials.
By tapping those links, the agency has positioned itself to collect at will from among hundreds of millions of user accounts, many of them belonging to Americans. The NSA does not keep everything it collects, but it keeps a lot.
According to a top-secret accounting dated Jan. 9, 2013, the NSA’s acquisitions directorate sends millions of records every day from Yahoo and Google internal networks to data warehouses at the agency’s Fort Meade, Md., headquarters. In the preceding 30 days, the report said, field collectors had processed and sent back 181,280,466 new records – ranging from metadata, which would indicate who sent or received emails and when, to content such as text, audio and video.
The NSA’s principal tool to exploit the data links is a project called MUSCULAR, operated jointly with the agency’s British counterpart, GCHQ. From undisclosed interception points, the NSA and GCHQ are copying entire data flows across fiber-optic cables that carry information between the data centers of the Silicon Valley giants.
The infiltration is especially striking because the NSA, under a separate program known as PRISM, has front-door access to Google and Yahoo user accounts through a court-approved process.
The MUSCULAR project appears to be an unusually aggressive use of NSA tradecraft against flagship American companies. The agency is built for high-tech spying, with a wide range of digital tools, but it has not been known to use them routinely against U.S. companies.
White House officials and the Office of the Director of National Intelligence, which oversees the NSA, declined to confirm, deny or explain why the agency infiltrates Google and Yahoo networks overseas.
In a statement, Google said it was “troubled by allegations of the government intercepting traffic between our data centers, and we are not aware of this activity.”
“We have long been concerned about the possibility of this kind of snooping, which is why we continue to extend encryption across more and more Google services and links,” the company said.
At Yahoo, a spokeswoman said: “We have strict controls in place to protect the security of our data centers, and we have not given access to our data centers to the NSA or to any other government agency.”
Under PRISM, the NSA already gathers huge volumes of online communications records by legally compelling U.S. technology companies, including Yahoo and Google, to turn over any data matching court-approved search terms. That program, which was first disclosed by the Washington Post and the Guardian newspaper, is authorized under Section 702 of the Foreign Intelligence Surveillance Act and overseen by the Foreign Intelligence Surveillance Court. Intercepting communications overseas has clear advantages for the NSA, with looser restrictions and less oversight. NSA documents about the effort refer directly to “full take,” “bulk access” and “high volume” operations on Yahoo and Google networks. Such large-scale collection of Internet content would be illegal in the United States, but the operations take place overseas, where the NSA is allowed to presume that anyone using a foreign data link is a foreigner.
Outside U.S. territory, statutory restrictions on surveillance seldom apply and the Foreign Intelligence Surveillance Court has no jurisdiction. Senate Intelligence Committee Chairwoman Dianne Feinstein, D-Calif., has acknowledged that Congress conducts little oversight of intelligence-gathering under the presidential authority of Executive Order 12333, which defines the basic powers and responsibilities of the intelligence agencies.
John Schindler, a former NSA chief analyst and frequent defender who teaches at the Naval War College, said it was obvious why the agency would prefer to avoid restrictions where it can.
“Look, NSA has platoons of lawyers and their entire job is figuring out how to stay within the law and maximize collection by exploiting every loophole,” he said. “It’s fair to say the rules are less restrictive under Executive Order 12333 than they are under FISA.”
The operation to infiltrate data links exploits a fundamental weakness in systems architecture. To guard against data loss and system slowdowns, Google and Yahoo maintain fortresslike data centers across four continents and connect them with thousands of miles of fiber-optic cable. These globe-spanning networks, representing billions of dollars of investment, are known as “clouds” because data moves seamlessly throughout them.
In order for the data centers to operate effectively, they synchronize high volumes of information about account holders. Yahoo’s internal network, for example, sometimes transmits entire email archives – years of messages and attachments – from one data center to another. Tapping the Google and Yahoo clouds allows the NSA to intercept communications in real time and to take “a retrospective look at target activity,” according to one internal NSA document.
In order to obtain free access to data center traffic, the NSA had to circumvent gold-standard security measures. Google “goes to great lengths to protect the data and intellectual property in these centers,” according to one of the company’s blog posts, with tightly audited access controls, heat sensitive cameras, round-the-clock guards and biometric verification of identities.
In an NSA presentation slide on “Google Cloud Exploitation,” however, a sketch shows where the “Public Internet” meets the internal “Google Cloud” where their data resides. In hand-printed letters, the drawing notes that encryption is “added and removed here!” The artist adds a smiley face, a cheeky celebration of victory over Google security. Two engineers with close ties to Google exploded in profanity when they saw the drawing. “I hope you publish this,” one of them said.
For the MUSCULAR project, the GCHQ directs all intake into a “buffer” that can hold three to five days of traffic before recycling storage space. From the buffer, custom-built NSA tools unpack and decode the special data formats that the two companies use inside their clouds. Then the data is sent through a series of filters to “select” information the NSA wants and “defeat” what it does not.
It is not clear how much data from Americans is collected, and how much of that is retained. One weekly report on MUSCULAR says the British operators of the site allow the NSA to contribute 100,000 “selectors,” or search terms. That is more than twice the number in use in the PRISM program, but even 100,000 cannot easily account for the millions of records that are said to be sent back to Fort Meade each day.
Asked about the Washington Post article in a public appearance, the NSA’s director, Army Gen. Keith B. Alexander, said Wednesday he was unaware of it, according to Politico – adding that the NSA is “not authorized” to access companies’ data centers and instead must “go through a court process” to obtain such content.
The leaked NSA documents, however, do not say the NSA accessed data centers. They say the NSA collected the data, including entire copies of Yahoo email accounts, as it was sent over fiber-optic lines between company data centers.