The correlation between an online shopper's comfort level with credit card number security and how much is actually spent on the Internet may be a good deal stronger than many analysts had thought, at least according to one look at consumer spending habits.

New York City-based Orbiscom, which markets what it calls Controlled Payment Number (CPN) technology, said that online shoppers spend two to four times more when they use substitute card number technology.

But regardless of the technology they use, consumers are spending. And for e-commerce retailers, "Black Friday" turned out to be "Black Monday" when online buyers returned to the privacy and speed of their workplace connections. Monday's online sales came in at an estimated $380 million, up 48 percent from last year, according to measurement firm comScore Networks.

And Black Friday itself was a nice boost for online sales as lots of consumers avoided mall madness and simply shopped the Web.

Orbiscom said it analyzed its own database of substitute card number users -- cardholders using CPN technology through card issuers such as clients such as Citibank, Discover and MBNA.

An analysis of consumers using this technology, comparing last year's second and third quarter Internet sales totals with this year's figures, shows an average increase in spending of about 220 percent compared with only 29 percent for the typical online shopper, Orbiscom said, citing figures from e-business research firm eMarketer.

eMarketer says its most recent figures show that 40 percent of those polled this year cited credit card number security issues as the main reason for not shopping online. And 56 percent of those who do shop online are concerned about having their data stolen from a merchant's database. Thirty-six percent said that just transmitting their credit card number over the Net was a concern.

Orbiscom's O-power product suite enhances existing payment cards by creating unique numbers for each online transaction. Citibank signed on as a user last June and launched what it calls Virtual Account Numbers, free to Citi Card cardmembers.

The virtual numbers are unique to a particular user-defined transaction and are linked back to the main card. The uniquely generated number, an O-number, means that the main card number is never revealed, Orbiscom says.

Orbiscom said eMarketer figures show that CPN users who spent between $101-$200 last year increased spending by an average of $658 this year. Consumers who spent over $1,000 online last year during the six-month period increased spending by an average of $1,184 -- more than doubling their Internet purchases.

"More consumers are shopping online than ever before, but at the same time, they know that the more they shop and spend online, the more vulnerable they become to online threats such as fraud and identity theft," said Diane Shaib, an executive vice president at Orbiscom.

She said that the study shows " that secure, convenient and flexible payment applications such as CPN act like a vitamin for online shoppers, giving them ... a boost of confidence to shop more and spend more."

In addition to Citybank, Orbiscom customers include MBNA, Discover, AIB, Swedbank and Credit Lyonnais