A Carlsbad company is using your buying past to protect your credit future.

BasePoint Analytics announced a deal within the last week to provide its historical analysis technology to protect MasterCard debit transactions. The privately held company did not release the terms of the deal.

For MasterCard, the technology tracks a customers' purchase history to catch thieves illegally using debit cards.

Linda Tecco, BasePoint's business development director, said in a telephone interview Tuesday that the system would help catch thieves in an industry where they are constantly adapting.

"Criminals are very savvy," she said. "It's always a challenge to stay one step ahead."

BasePoint uses proven, technology-tracking financial data and adapts it to a particular market or system. Regarding personal identification numbers, or PIN, debit-card transactions, the system tracks a customer's purchase the minute the card is used. Then it compares the purchase to the customer's history of purchases.

If a store purchase is outside normal buying behavior, the bank or financial institution that approves the purchase notifies the store that the buyer could be using the card illegally. The store would have the option of asking for more identification before accepting the purchase or notifying authorities.

Fraud can translate to big bucks for criminals. Gartner Inc., an information technology research company in Connecticut, estimated that ATM/debit-card fraud cost consumers and businesses $2.8 billion during the year ended May 2005.

BasePoint works with financial institutions to prevent other types of ATM/debit-card crime, such as skimming. Criminals "skim" cards using a small card reader placed on top of an ATM's standard card reader. The device reads the magnetic strip on the back while the criminal watches the victim from a nearby location with binoculars, or other such device, to read the PIN number. Then the criminal uses the data and PIN to make a phony card and withdraw money.

Tecco, BasePoint's director, said catching criminals is one aspect that makes her job fun.

"It's nice to be able to … protect financial institutions and customers," she said.

- Contact staff writer Patrick Wright at (760) 739-6675 or pwright@nctimes.com.