HSBC Holdings PLC is using a phone authentication system from the Chicago security technology vendor Authentify Inc. to protect online and remote transactions from fraud.

The "out-of-band" system requires details about the user or the transaction to be entered by telephone, while the transaction is under way, to authenticate users attempting "certain transactions," Authentify said Monday.

"Using a telephone call synchronized to an online session provides a simple, reliable way to strengthen an online process" with technology that people "already own and know how to use," Peter Tapling, Authentify's president and chief executive, said in a press release.