In the chaotic days after the June election in Iran, the State Department asked Twitter to put off maintenance of its global network, which would have cut off service to Iranians using it to swap information and tell the world about antigovernment protests. The administration’s move will not deprive the Iranian authorities of the ability to clamp down on the Internet, as happened in February, when service was constricted so heavily that Iranians had difficulty accessing Gmail accounts and organizing protests before the 31st anniversary of the Iranian Revolution. But by offering Iranians more options, the official said, it will force the authorities in Iran to plug more holes.

“We want to make sure the information flows,” he said. “It will obviously have political implications in a range of ways.”

The administration’s blanket waiver does not apply to encryption and other software that makes it harder for the authorities to track people’s Internet activity. That category of technology does not fall within the mass-market services that can be downloaded free from the Internet, he said.

But the official said the Treasury would grant licenses to such providers on a case-by-case basis, and would generally look favorably on them. One such service, known as Haystack, is awaiting a waiver from the State Department, and is subsequently likely to obtain a Treasury license.

Developed by the Censorship Research Center, a San Francisco-based nonprofit organization, Haystack uses mathematical formulas to disguise a user’s Internet traffic from official censors.

In December, Representative James Moran, Democrat of Virginia, introduced a bill in the House that would “support the democratic aspirations of the Iranian people by enhancing their ability to access the Internet and communications services.” It also calls for the United States to give tools to Iranians to help circumvent government restrictions on the Internet.

The State Department says it is working in 40 countries to help people get around these barriers. But critics said it had moved slowly in spending $15 million appropriated by Congress in 2008 to support these programs.