WASHINGTON -- In room-size metal boxes, secure against electromagnetic leaks, the National Security Agency is racing to build a computer that could break nearly every kind of encryption used to protect banking, medical, business and government records around the world.
According to documents provided by former NSA contractor Edward Snowden, the effort to build "a cryptologically useful quantum computer" -- a machine exponentially faster than classical computers -- is part of a $79.7 million research program, titled "Penetrating Hard Targets." Much of the work is hosted under classified contracts at a laboratory in College Park, Md.
Development of a quantum computer has long been a goal of many in the scientific community, with revolutionary implications for fields such as medicine as well as for the NSA's code-breaking mission. With such technology, all forms of public key encryption would be broken, including those used on many secure websites as well as the type used to protect state secrets.
Physicists and computer scientists have long speculated whether the NSA efforts are more advanced than those of the best civilian labs. Although the full extent of the agency's research remains unknown, the documents provided by Mr. Snowden suggest that the NSA is no closer to success than others in the scientific community.
Meanwhile, The New York Times and Guardian newspapers have each called for clemency for Mr. Snowden, saying he should be praised rather than punished for his disclosures.
The papers -- both of which have played a role in publishing Mr. Snowden's intelligence trove -- suggested late Wednesday that his revelations about the United States' world-spanning espionage program were of such public importance that they outweighed any possible wrongdoing.
Mr. Snowden now resides in Russia after an abortive bid to travel to Latin America, where he had been offered asylum. He faces espionage charges in connection with his leaks, which U.S. officials have described as damaging or even life-threatening, but amnesty rumors have been circulating for several weeks after the idea was first floated by senior NSA official Rick Leggett.
"Considering the enormous value of the information he has revealed, and the abuses he has exposed, Mr. Snowden deserves better than a life of permanent exile, fear and flight," the Times said, urging either a plea bargain, some form of clemency or a "substantially reduced punishment."
The Guardian said it hoped "calm heads within the present [U.S.] administration are working on a strategy to allow Mr. Snowden to return to the U.S. with dignity, and the president to use his executive powers to treat him humanely and in a manner that would be a shining example about the value of whistleblowers and of free speech itself."
Both newspapers published their editorials online within a few hours of one another, but Guardian editor Alan Rusbridger said the papers' appeals were not coordinated ahead of time.
On the encryption front, the NSA appears to regard itself as running neck and neck with quantum computing labs sponsored by the European Union and the Swiss government, with steady progress but little prospect of an immediate breakthrough. "The geographic scope has narrowed from a global effort to a discrete focus on the European Union and Switzerland," one NSA document states.
Seth Lloyd, a professor of quantum mechanical engineering at the Massachusetts Institute of Technology, said the NSA focus is not misplaced.
"The EU and Switzerland have made significant advances over the last decade and have caught up to the U.S. in quantum computing technology," he said.
The NSA declined to comment for this story. But the documents indicate that the agency carries out some of its research in large, shielded rooms known as Faraday cages, which are designed to prevent electromagnetic energy from coming in or out. Those, according to one brief description, are required "to keep delicate quantum computing experiments running."
Here's how it works, in theory: While a classical computer, however fast, must do one calculation at a time, a quantum computer can sometimes avoid having to make calculations unnecessary to solving a problem. That lets it home in on the correct answer more quickly and efficiently.
A working quantum computer would open the door to breaking the strongest encryption tools in use today, including a standard known as RSA, named for its creators' initials. RSA scrambles communications, making them unreadable to anyone but the intended recipient, without requiring a shared password. It is commonly used in Web browsers to secure financial transactions and in encrypted emails.
RSA is used because of the difficulty of factoring the product of two large prime numbers. Breaking the encryption involves finding those two numbers. This cannot be done in a reasonable time on a classical computer.
A large-scale quantum computer, however, could theoretically break a 1,024-bit encryption much faster. Some leading Internet firms are moving to 2,048-bit keys, but even those are thought to be vulnerable to rapid decryption with a quantum computer.
Associated Press contributed.