For millions around the globe, a winning number in the green card lottery is seen as a chance to cash in on the American dream.

The December 4 deadline to enter the lottery is approaching, and tensions are rising, as is the number of scams to rip off eager immigrants.The lottery is now entirely online, a shift that helped decrease the number of multiple entries by single filers but facilitated electronic cons. Warnings are being issued from Barbados to Ireland to the Queens Library about swindlers luring unsuspecting immigrants into upfront fees with false guarantees that they will then be able to “live and work in USA.”

It’s not hard to find shady dealers. When “diversity lottery” is typed into one popular Internet search engine, dozens of services appear that charge for what is a free application – some as much as $500. The Federal Trade Commission issued an alert earlier this year, saying, “If you or someone you know is trying to get a green card – the right to live in the United States permanently – be on the lookout for unscrupulous businesses and attorneys.”

Green card lottery scams are a familiar story at the Emerald Isle Immigration Center in Queens.

“Every year right around this time, an e-mail blast will come to people in the immigration field guaranteeing a green card,” the executive director of the center, Siobhan Dennehy, said.

Congress created the green card lottery program in 1990. At the time, it especially benefited Polish and Irish immigrants, reserving 40% of winners for citizens of Ireland. By the time the Diversity Lottery was instituted in its current form a decade ago, however, it had been transformed into a program that benefited immigrants from countries that have smaller populations coming to America.

Last year, Ethiopians won the most green cards with 6,995, followed by Egyptians (6,439) and Moroccans (5,980). The Irish, by contrast, won 145 visas.

In December, a computer will select about 90,000 winners at random from a pool of millions of applicants from around the world. Only about 50,000 permanent residency visas are expected to be distributed because in the past, nearly half did not qualify for or choose to pursue their visas.To qualify, the immigrant must be from a country that has sent less than 50,000 people to America over the past five years, and the applicant must have a high school diploma or two years’ work experience.

Applicants for a chance at permanent residency can apply from America or abroad. Illegal immigrants have won, but in order to get a green card, in most cases they must return to their native country and hide any evidence that they broke American immigration law.

Supporters say that despite problems with fraud, the program has succeeded in its mission – ensuring a diverse pool of immigrants to America.

“This program has marked the first time in our history that Africans have been able to immigrate by choice in significant numbers,” a former Democratic congressman from Connecticut, Bruce Morrison, said in congressional testimony on the program last summer. “During the Cold War, we berated the Warsaw Pact countries for denying emigration rights to their citizens. The diversity visa has actually allowed immigration from this region to resume.”

Critics, however, warn that security-risk nations have had a high number of winners, and say immigrants should have to prove why they merit coming to America – not be picked out of an electronic hat. Indeed, a disproportionate number of winners have come from nations that the American government has distinguished as state sponsors of terrorism: Almost 1,900 were selected in the 2005 lottery. Moreover, two winners have been associated with terrorism: an Egyptian who killed two in an attack at LAX in 2002, and a Pakistani who pleaded guilty in August 2002 to conspiracy to destroy electrical power stations in Florida.