WASHINGTON, D.C. — How smart do you want your smart card to be?

Do you want convenience — a card that establishes who you are on the fly? Or do you want security — a card that can't be skimmed by a spy?

Take your time. Border security, illegal immigration, privacy and a lot of money are riding on your answer.

There's a technology debate under way in Washington between the departments of State and Homeland Security over how smart Pass (People Access Security Service) cards should be.

Pass cards would let U.S. commuters, day-trippers and others who cross the border into Mexico or Canada come and go without using a more elaborate and expensive passport. You can cross today with a driver's license or a birth certificate, and U.S. border agents seized 75,000 fake IDs last year.

To curb immigrant counterfeiting and filter out would-be terrorists, every American will need either a passport or a Pass card to ride or walk across the border by Jan. 1, 2008.

(If you travel by ship or plane, you'll need a passport, and you'll need it by Jan. 8, 2007.)

The plastic Pass cards will include a microprocessor that emits unique information when zapped by radio waves from a U.S. Customs and Border Protection scanner. Companies that make the microprocessors, scanners, antennae and operating systems for these cards, such as Texas Instruments and Symbol Technologies, say the cards are nearly impossible to counterfeit. But they have very different opinions about which types make the best ID cards.

Homeland Security and New York-based Symbol Technologies want cards that will send back a number key to unlock a government database and reveal a photo and other identity information on the computer screen of a federal border agent.

TI's product

The State Department and Texas Instruments prefer a more elaborate card with a chip that has its own database. The chip would hold an encrypted digital photo and other identity details that can be decoded and read by scanners in use by border agents around the world.

Potential proceeds for TI, Symbol Technologies and others are sizable. One industry group estimates that state and local governments will spend $2.5 billion on smart card technology through 2012.

Both versions of the card use radio-frequency identification microprocessors. But they reveal their contents at different frequencies and different distances. Homeland Security's prototype, made by Symbol Technologies, responds to ultra-high-frequency waves that can pick up the card number from an overhead road sign or other station as far as 30 feet away.

The State Department's card uses high-frequency technology. Known as a "contactless card," it has to be waved within 4 inches of a scanner for the border agent to unlock its data.

New U.S. passports include these chips, made by the German company Infineon Technologies and Holland's Royal Philips Electronics. "We were a little late coming to that competition," said Texas Instruments' Tres Wiley.

Homeland Security's acting deputy director for border technologies, P.T. Wright, says Pass cards that can be read at a distance would do the most to ease border congestion. More than 120 million people legally cross between Texas and Mexico every year, and each crossing can take hours.

Homeland Security is studying both types of Pass cards at the border crossing in Nogales, Ariz., where wait times of two hours are not uncommon. Travelers using Pass cards with the type of chips included in electronic passports have seen that wait cut in half, while those with cards that can be read at a distance wait as little as 19 minutes, Mr. Wright said.

Distance question

Texas Instruments and others that specialize in smart cards that have the data is included in the microprocessor say distance-read cards are a security risk. A spy using an antenna could skim the signal, and use it to stalk the vehicle it came from, said Mr. Wiley.

It's a concern reflected in a Homeland Security spending bill passed by the Senate. The bill includes a provision favoring the Pass card technology preferred by the State Department and would delay the whole passport/Pass card requirement until June of 2009.

Mr. Wright, who hopes this debate will be settled in a couple weeks, doesn't think skimming will be a problem with cards read at a distance.

The cards emit a unique 96-bit number: "If you have all the dogs in the world and you counted all the hairs on all those dogs, well, that's where that number comes from," Mr. Wright said. "Somebody could skim to get the number, it would be nonsensical. There's no identity information with it."

Next up after Pass cards will be standards for electronic driver's licenses and other state-issued identity documents. The winner of the Pass card round hopes to get a boost into other applications of the $3 billion smart card business.

E-mail jlanders@dallasnews.com