The agency has circumvented or cracked much of the encryption, or digital scrambling, that guards global commerce and banking systems, protects sensitive data like trade secrets and medical records, and automatically secures the e-mails, Web searches, Internet chats and phone calls of Americans and others around the world, the documents show.
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Many users assume — or have been assured by Internet companies — that their data is safe from prying eyes, including those of the government, and the N.S.A. wants to keep it that way. The agency treats its recent successes in deciphering protected information as among its most closely guarded secrets, restricted to those cleared for a highly classified program code-named
Bullrun, according to the documents, provided by Edward J. Snowden, the former N.S.A. contractor.
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The N.S.A. hacked into target computers to snare messages before they were encrypted. And the agency used its influence as the world’s most experienced code maker to
covertly introduce weaknesses into the encryption standards followed by hardware and software developers around the world.
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“We are investing in groundbreaking cryptanalytic capabilities to defeat adversarial cryptography and exploit Internet traffic,” the director of national intelligence, James R. Clapper Jr., wrote in his budget request for the current year.
Some of the agency’s most intensive efforts have focused on the encryption in universal use in the United States, including Secure Sockets Layer, or SSL, virtual private networks, or VPNs, and the protection used on fourth generation, or 4G, smartphones.
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For at least three years, one document says, GCHQ, almost certainly in close collaboration with the N.S.A., has been looking for ways into protected traffic of the most popular Internet companies: Google, Yahoo, Facebook and Microsoft’s Hotmail. By 2012, GCHQ had developed “new access opportunities” into Google’s systems, according to the document.
Paul Kocher, a leading cryptographer who helped design the SSL protocol, recalled how the N.S.A. lost the heated national debate in the 1990s about inserting into all encryption a government back door called the Clipper Chip.
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And they went and did it anyway, without telling anyone,” Mr. Kocher said.