The NSA used to target only foreign signals, and according to its own legal interpretations, that's what it still does. But communications are now global: the Internet is so interconnected that everything and everyone on the network becomes a potential target, even the network itself. That's not to say that the NSA has "broken" all cryptography: "the math works," says Schneier, and while anonymizing tools like Tor are targeted by NSA, they seem to remain secure. Instead, the NSA appears to have manipulated encryption tools and tapped into data center links and fiber backbones—in essence, silently removing the hinges from their doors.
"We do know they made a systematic effort to place back doors in the products we use to get our security, and that makes us all less safe," he said. Schneier, like others in the cryptography community, regularly trades hunches and suspicions about NSA encryption exploits, and the National Institute for Standards and Technology, the federal group that sets encryption standards, is reviewing its past work in light of the NSA scandal. But few know for sure just how widespread the NSA's targeting of encryption standards is. And, Schneier worries, those who do know might not necessarily be well-intentioned.