NEW YORK — More Target-size security breaches will happen if banks and retail stores don’t start working together to further protect customers’ data, JPMorgan Chase’s chief executive, Jamie Dimon, said Tuesday.
JPMorgan has replaced 2 million credit and debit cards as a result of the breach, Dimon said in his first public comments about the event. The bank has replaced nearly all the affected cards.
JPMorgan is the world’s largest issuer of credit cards.
Dimon expects that cybercrimes such as the Target breach will become more common if retailers and banks do not work on security.
‘‘This story is not over, unfortunately,’’ Dimon said in a conference call with investors.
In December, Target said 40 million credit and debit card accounts — including customers’ card numbers, expiration dates, debit-card PINs, and the embedded code on the magnetic strip on the back of cards— were stolen in a data breach that happened between Nov. 27 and Dec. 15.
Last week, the company disclosed that hackers stole an additional trove of data affecting 70 million people. That data included names and phone numbers, e-mail and mailing addresses. The company said there is some overlap between the two data sets.
It is the second-largest theft of shoppers’ credit card data, following the theft of 90 million customers’ data from the Massachusetts-based discount retailer TJX Cos. in 2007.
Dimon said the bank hasn’t seen a reduction in consumer spending due to the breach, and there are no signs that consumers moved to other forms of payment, like cash or checks. The breach is not expected to affect JPMorgan’s financial results, a spokeswoman said.
Dimon said he expects that banks will issue cards with more security features on them in the future.
Banks and the stores that accept their credit and debit cards have had a complicated relationship for years. Stores want to accept credit and debit cards because it’s often a customer’s preferred form of payment. But every time a shopper swipes a credit or debit card, a bank charges a small fee. That interchange fee adds up to billions of dollars in revenue for the banks. It’s why businesses like gas stations charge customers more to use credit or debit cards versus cash.
The attorneys general of Connecticut and Illinois, whose offices are leading a multistate investigation in the Target breach, are also looking into the hack of Dallas-based Neiman Marcus, which said on Friday that some unauthorized purchases may have been made with credit cards.