The U.S. government will soon be issuing new, high-technology identification cards to more than ten million people in the federal work force. The move is prompting a debate over whether the work I.D.s represent the first step toward a national identification card.

Tom Greco, the vice president of CyberTrust, a technology firm located near Washington, D.C., says most Americans carry some kind of simple identification document -- a driver's license or a passport, for instance. "Those typically tend to be plastic,"  he says, "with some kind of photograph on them.  What most people in the 'high technology' field would consider 'dumb' I.D.s.'"

Mr. Greco says his company and about 15 other firms have designed and manufactured new, high tech, so-calledly defined as a plastic card with a computer chip on it. That chip can contain the name, perhaps the affiliation of the person, like with what federal agency. It can also contain information like a digitized photo or a 'biometric' -- like a set of fingerprints. Things like that."

The government's new smart-card I.D.s are the latest and, in the United States, the broadest use so far of biometric technology that recognizes a person's physical features. Greco says the new federal I.D. will identify individual fingerprints. "In the case of the card that'll be produced for federal employees and contractors," he notes, "your fingerprints can be read by scanners. Present the finger at the [machine] reader, and it just scans it and can match it on the card. The smart card is capable of doing that kind of biometric verification."

Greco says the reason the government is implementing a new smart-card identification system is to protect federal employees, buildings, and information systems from a terrorist attack, because the 9/11 terrorist attacks showed conventional I.D. systems were ineffective. "In the wake of terrorist exploitation of infrastructure," Greco observes, "certain terrorists were able to get access to the planes using forged state driver's licenses. The impetus is to protect both the physical assets of the U-S government and the logical computer assets of the U-S government. Using current technology was viewed as the way to go."

But is it the way to go? Jay Stanley is a spokesman for the American Civil Liberties Union, or A.C.L.U. "A national I.D. card is something that Americans have resisted all throughout our history," Stanley says. "It is something that will be used to regiment Americans, track Americans, used to set up systems of access control throughout our country. It really becomes tantamount to an internal passport."

Cards similar to the new federal worker I.D. will eventually be issued to tens of millions of other public employees such as transportation workers, emergency medical personnel, as well as police and firefighters. Visitors to the United States will also be issued smart I.D. cards. And national legislation passed by Congress in 2005 requires all state governments to convert their motor vehicle licenses to smart cards by 2008, putting the new IDs into the purses and wallets of 9 out of every 10 Americans. The A.C.L.U.'s Jay Stanley argues this use of smart cards would go too far. "As an employer, of course, the federal government can issue I.D.s and passes to its employees like any other employer," he says. "But when you are talking about the federal government, it is such an enormous and often standard-setting body that it does cause extra concern."

But even such widespread use of smart-card IDs does not necessarily mean we're headed down a slippery slope toward a national ID system, according to Todd Gaziano, the director of the Center for Legal and Judicial Studies at the Heritage Foundation, a conservative think tank in Washington, D.C. Gaziano says that with public approval, precautionary measures need to be taken. "People have repeatedly shown they are willing to give up information to providers of services -- so it's just not the case that most people are terribly concerned about this. But more important for flight safety," adds Gaziano, "is that we need to make sure there aren't fraudulent documents. It's just as simple as that. Those who see slippery slopes (toward the loss of civil liberty) in this program will see slippery slopes anywhere and everywhere."

Gaziano also supports the federal government's directive to the states to apply smart card technology to driver's licenses. The alternative, in his view, would have dire consequences for national security and civil liberties down the road. "If people do not go along with reasonable improvements in security," he warns, "we will lose much more in the way of privacy and civil liberties after the next attack."

Jay Stanley of the A.C.L.U. predicts many state legislatures will balk at complying with the federal mandate -- at the very least, because of the higher fees and taxes needed to pay for the smart-card conversions.

Tom Greco of the technology firm CyberTrust sees an international trend in high-tech credentialing. "In a number of countries," Greco notes, "particularly in Europe and the Far east, for almost a decade now there've been initiatives to move the traditional paper or plastic I.D. card to more of the 'smart' format. In Belgium, for example, almost five million people in the population credentialed with this kind of card -- that contains information on name, age, and I.D. numbers -- that can be read by a computer and validated that the I.D. is current. Malaysia, Singapore -- a number of the Asian countries -- also have very robust national I.D. cards that are based on smart cards. Italy is another country that has moved down this technology path. Sometimes it's just the confluence of the ability, the technology being present, and the wherewithal to move in this direction.

But there's also spirited debate about the issue in many democratic countries around the world. Many countries have smart cards to make it easier for their citizens to keep track of banking transactions and health insurance coverage -- and gain access to public transportation and telephones -- but have largely stopped short of creating a smart national I.D.. In the United Kingdom, for instance, there's so far been a reluctance to introduce a high-tech, national I.D. system designed to protect citizens from terrorism because of critics' concerns the potential threat to individual liberties.