Forget about a national ID card. Instead, the federal government might use Microsoft's Passport technology to verify the online identity of America's citizens, federal employees and businesses, according to the White House technology czar.

On Sept. 30, the government plans to begin testing Web sites where businesses can pay taxes and citizens can learn about benefits and social services. It's also exploring how to verify the identity of users so the sites can share private information.

Microsoft's Passport is being considered as a way to authenticate users of the Web sites, said Mark Forman, associate director of information technology at the White House.

"They are involved in that discussion,'' he said, adding that the government has not yet selected which technology it will use.

Forman, who is overseeing the government's purchases of $100 billion worth of technology this year and next, was a featured speaker at the Microsoft Government Leaders Conference in Seattle this week.

Forman is a former Senate staffer who worked for IBM and Unisys before he joined the Bush administration.

Describing himself as the government's chief information officer, he said his priorities are to impose businesslike approaches for technology deployments and to monitor improvements they bring.

After the Sept. 11 attacks, some politicians and business leaders have called for a national identification card, but Forman said that's not in the works. "We don't have any plans for a national ID card," he said.

The White House is instead pursuing an "e-identification" initiative, an effort to develop ways to authenticate people and businesses online who already have government identification numbers such as Social Security, business-registration and employer-identification numbers.

At the government-leaders conference, attended by representatives of 75 countries, Microsoft presented a blueprint for its "e-government" strategy that suggests they use Passport to verify the identity of visitors to their Web sites. It also suggested that its bCentral business Web site could be used to process business tax payments and that citizens could use its MSN Web site to handle address changes and voter registration.

Governments have long been some of Microsoft's biggest customers. Its desktop software for office workers and back-end software running networks are widely by used by state and federal agencies, and the company has developed Internet portals for the United Kingdom, Mexico and other nations.

But getting the United States to use Passport to authenticate its 285 million citizens online would be a coup for the Redmond software company. It would also be a large step toward fulfilling Microsoft Chairman Bill Gates' stated goal of getting everyone on the Internet to use Passport as their sign-on tool.

Yesterday, appearing at the conference, Gates reiterated the goal, saying he expects governments in many countries will find it difficult getting to "critical mass" with authentication systems they develop on their own. He said some governments may opt to use companies such as Microsoft or America Online as "the bank" that registers people for online usage.

Passport was introduced in 1999 and is the keystone of an array of online services the company introduced a year ago, when Gates revealed his ambitions for the service.

After privacy advocates attacked the plan and a coalition of major corporations formed an alliance to develop standards for authentication systems that would work together, Microsoft toned down its approach. It now acknowledges that Passport will co-exist with other tools.

Forman said his team has also been contacted by the coalition, called the Liberty Alliance, and will meet with them at some point.

The current version of Passport requires little personal information other than an e-mail address, but a new, more secure version expected by mid-2003 may be used to store sensitive data on Microsoft's network.

Microsoft says it has 200 million people registered to use Passport, most of whom signed up because Microsoft told them it was needed to use other Microsoft services, such as its free Hotmail e-mail service or Windows XP operating system. According to Gartner, a research company based in Stamford, Conn., only 2 percent signed up because of the service's stated purpose: to avoid having to use multiple identifications and passwords at different Web sites.

Avivah Litan, vice president and research director at Gartner, said expanding Passport benefits Microsoft by drawing more Web traffic, making its sites more appealing to advertisers and enabling the company to charge "click through" fees for online sales executed using the service.

But the company may ultimately decide it's not worthwhile to boost the service from a tool of convenience for consumers to a verification service relied upon by businesses and government.

"Once you start vouching for identity, that makes you liable for fraud, that makes you liable for identity theft," Litan said.

Also at the conference, Microsoft announced plans to bring Internet access to government services to Mexico through a network of kiosks developed with the company's technology.