CHICAGO — Because she was born in Chicago,Karen Peiskernever imagined her bosses at the United Parcel Service would suddenly question her right to work in the country legally.

But last month, an electronic employee verification system flagged the mail truck driver for possible identity fraud because she had been using her married name, Rivera, on her driver’s license since 2007. Though Peisker joined the company in 1985, it put her at risk of being fired until she proved she was who she said she was.

“”I couldn’t believe it,”” said Peisker, 50, who repeatedly had to show up to work with her birth certificate, marriage license and U.S. passport until the confusion was cleared up.

Not uncommon, such problems with the federal E-verify software system — intended to pluck illegal immigrants out of the work force — have led to proposals for a more wide-reaching solution that could be as culturally transformative as it is controversial. Until recently, it also might have seemed as futuristic as aSteven Spielbergmovie thriller.

Two U.S. senators prominent in immigration reform efforts have proposed that all Americans be issued biometric Social Security cards, containing codified data from either a fingerprint or retinal scan to help employers determine whether the holder is legal.

In explaining the only current bipartisan reform proposal, Sen.Charles Schumer, D-N.Y., has called such a high-tech Social Security card “”a linchpin”” in efforts to win support in Congress for fixing an immigration enforcement system that many agree is broken. Immigrant advocates are pushing for action on immigration reform this year, and the Obama administration has expressed support, though many analysts doubt the current political climate is conducive.

While details are still sketchy, Schumer and Sen.Lindsay Graham, R-S.C., have proposed that the new Social Security card be swiped by employers through a machine to match a fingerprint or some other personal biometric feature against data stored on computers. Those who refuse to cooperate or otherwise knowingly hire unauthorized workers would face fines and even prison.

Privacy groups call the idea chilling, and costly. Last week, 44 organizations sent a letter of protest to the White House and both senators, arguing that implementation of a biometric card could cost “”hundreds of billions of dollars.””

Chris Calabrese, legislative counsel for the American Civil Liberties Union, labeled the proposal a form of “”mission creep”” that would pull the country down a dangerous path.

“”We think that card would quickly spread to other purposes from voting to gun ownership to travel, and it will really be a permission slip for participating in American life,”” Calabrese said.

Schumer and Graham have taken pains to address the privacy concerns. In an outline published last month in The Washington Post, they said biometric information would only be stored on the card and not warehoused in any government database, though critics argue that biometric information would have to be stored somewhere to prevent identity fraud or to confirm a person’s identity in the event of a lost Social Security card.”” The cards would not contain private information or tracking devices, the legislators asserted.

In a rare meeting of minds, some advocates on both sides of the combative reform debate are open to the idea.

“”We need to know who’s working in the United States, and we need to make it easy,”” argued U.S. Rep.Luis Gutierrez, D-Ill.

Dan Stein, president of the Washington-based Federation for American Immigration Reform, which supports reducing all immigration, said: “”We, in principle, are not averse to the application of technology responsibly used.””

The embrace of the biometric Social Security card idea lies at least partly in frustrations surrounding the E-verify system, a 13-year-old federal program that is mandated for employers by some states.

Nearly 200,000 companies use E-verify, with about 1,000 new employers signing up per week, U.S. officials say. Last September, the Obama administration began requiring that 26,500 federal contractors and subcontractors sign up.

The E-verify software system checks an employee’s identification by matching the documents provided by that worker against Social Security Administration records. In cases where there is a “”mismatch,”” the worker has eight days to prove their identity or risk being fired.

But in 4 percent of cases, the system wrongly flags legal workers for potential fraud. And in a January evaluation for the Department of Homeland Security, it failed to flag illegal workers using fake IDs more than half the time.

In Chicago, anger over the system fueled a protest earlier this month in front of UPS’s distribution center on the Near West Side. There, workers fired for refusing to submit their IDs to be electronically confirmed were among a small crowd staging a 24-hour “”hunger strike.””

Company officials wouldn’t say how many employees were fired for not cooperating, though union representatives at UPS said the total is at least 90. Some protestors accused the company of using E-verify only to get rid of workers it can no longer afford in a bad economy.

UPS spokesmanNorman Blacksaid the Atlanta-based company of 340,000 employees is required as a federal contractor to use E-verify. “”I had to do (submit to verification) it. Everybody in headquarters had to do it. Everybody in the country had to do it,”” Black said.

The dispute illustrated a quandary for employers, who find themselves navigating between immigration laws and federal labor and discrimination laws. In recent years, many companies have been accused of overreacting to E-verify by grilling workers whose names were flagged, or pre-emptively firing them before they had a chance to prove they’re legal.

“”You can, as an employer, be kind of betwixt and between in terms of asking for too much information or not asking enough,”” saidMike Aitken, director of government affairs for the Society for Human Resource Management, a Virginia-based umbrella group for 250,000 human resource professionals.

Aitken’s group opposes E-verify and a biometric Social Security card. Instead, the group has lobbied for federal legislation that would incorporate a biometric approach similar to what Wall Street corporations and high-security companies use — systems in which data is stored privately and expunged at a worker’s request.

Gerri Ratliff, who oversees E-verify at U.S. Citizen and Immigration Services, said her agency is evaluating whether a biometric approach could be incorporated into the existing software — even if immigration reform efforts stall again this year. Already, the E-verify system checks photos on green cards and other IDs issued by Homeland Security, she said.

For Peisker, a mail trailer truck driver who now has switched back to using her maiden name because of the E-verify problem, the whole identification discussion is disturbing.

“”I do not have an ATM card. I do not have automatic deposit. I do not have anything that puts my name on a computer with a Social Security number, if I could help it,”” Peisker said. “”I’m really upset about this.””