The PCI Security Standards Council said on Monday it is to produce additional guidelines to cover unattended payment terminals, such as those found in vending machines and on fuel pumps.
Previously the guidelines only covered point-of-sale devices which are attended by a member of staff.
The additions mean extra requirements for retailers, which will now need to secure their systems not only in datacentres and stores, but at all terminals where a PIN is entered.
Though the PCI Standards Council did not mention last year's hack on international retail giant TJX, which reportedly started through a store kiosk, such incidents have raised concerns over the security of point-of-sale terminals.
"PIN entry devices go well beyond the typical POS terminals that we are all familiar with and we are continually expanding into more and more areas," said Bob Russo, general manager of the PCI Security Standards Council, which was founded by credit card giants American Express, MasterCard and Visa. "Any device that processes personal identification numbers is an important link in the transaction chain."
As well as unattended point-of-sale terminals, the new guidelines will cover hardware security modules (HSMs), which are cryptographic devices that can be used for PIN translation, card personalisation, electronic commerce or data protection.
The PCI standards have just passed a critical deadline. As of Monday, they now state that web application security testing is a requirement, rather than purely best practice.
Critics, including HP's senior security consultant Joey Peloquin, argued that few retailers had beenprepared for that deadline.
Companies that are not in compliance with the latest payment card standards risk fines of potentially millions of dollars.