Representative Rush D. Holt Jr., a New Jersey Democrat who is also a physicist, said on Friday he believed that the N.S.A. was overreaching and could hurt American interests, including the reputations of American companies whose products the agency may have altered or influenced.
“We pay them to spy,” Mr. Holt said. “But if in the process they degrade the security of the encryption we all use, it’s a net national disservice.”
Mr. Holt, whose Surveillance State Repeal Act would eliminate much of the escalation in the government’s spying powers undertaken after the 2001 terrorist attacks, was responding to news reports about N.S.A. documents showing that the agency has spent billions of dollars over the last decade in an effort to defeat or bypass encryption. The reports, by The New York Times, ProPublica and The Guardian, were posted online on Thursday.
The agency has encouraged or coerced companies to install back doors in encryption software and hardware, worked to weaken international standards for encryption and employed custom-built supercomputers to break codes or find mathematical vulnerabilities to exploit, according to the documents, disclosed by Edward J. Snowden, the former N.S.A. contractor.
The documents show that N.S.A. cryptographers have made major progress in breaking the encryption in common use for everyday transactions on the Web, like Secure Sockets Layer, or SSL, as well as the virtual private networks, or VPNs, that many businesses use for confidential communications among employees.
Intelligence officials say that many of their most important targets, including terrorist groups, use the same Webmail and other Internet services that many Americans use, so it is crucial to be able to penetrate the encryption that protects them. In an intense competition with other sophisticated cyberespionage services, including those of China and Russia, the N.S.A. cannot rule large parts of the Internet off limits, the officials argue.
A statement from the director of national intelligence, James R. Clapper Jr., criticized the reports, saying that it was “not news” that the N.S.A. works to break encryption, and that the articles would damage American intelligence collection.
The reports, the statement said, “reveal specific and classified details about how we conduct this critical intelligence activity.”
“Anything that yesterday’s disclosures add to the ongoing public debate,” it continued, “is outweighed by the road map they give to our adversaries about the specific techniques we are using to try to intercept their communications in our attempts to keep America and our allies safe and to provide our leaders with the information they need to make difficult and critical national security decisions.”
But if intelligence officials felt a sense of betrayal by the disclosures, Internet security experts felt a similar letdown — at the N.S.A. actions.
“There’s widespread disappointment,” said Dan Kaminsky, a prominent security researcher. “This has been the stuff of wild-eyed accusations for years. A lot of people are heartbroken to find out it’s not just wild-eyed accusations.”
Mr. Kaminsky said that there had been “a tremendous amount of good will between the cryptographic community and N.S.A. that’s built been up,” referring to experts on encryption. “That is gone,” he said.
Sascha Meinrath, the director of the Open Technology Institute, a research group in Washington, said the reports were “a startling indication that the U.S. has been a remarkably irresponsible steward of the Internet,” which he said the N.S.A. was trying to turn into “a massive platform for detailed, intrusive and unrestrained surveillance.”
Marc Rotenberg, the executive director of the Electronic Privacy Information Center, a civil liberties group in Washington, said the quandary posed by the N.S.A.’s efforts against encryption began with its dual role: eavesdropping on foreign communications while protecting American communications.