Banks need to take a hard look at the age-old practice of using signatures to authenticate card payments, Federal Reserve Gov. Jerome Powell said Thursday.

In a speech delivered at a Federal Reserve Bank of Kansas City conference in Missouri, Powell suggested banks are taking half measures to improve payment security. While the issuance of chip cards to replace magnetic stripes is progress, the chip-and-signature cards U.S. banks have been distributing to customers are less secure than the chip-and-PIN cards standard in other parts of the world.

"The deployment of EMV chip cards in the United States represents an important step forward. But we should not stop there," he said. "New approaches to authentication increasingly offer greater assurance and protection. Given the current technologies that we have at our disposal, we should assess the continued use of signatures as a means of authenticating card transactions."

Visa and MasterCard have set an Oct. 1 deadline for merchants to implement the technology to process chip cards or else assume liability for in-store card fraud.

Powell called the deployment of chip cards "good defense," but said it will take more than that to foil an inevitable attack — banks need to "layer security tools and procedures," he said, "methods to devalue payment data, like tokenization and encryption for data at rest, in use, and in transit, mitigate the effect of a data breach."

Advocates of signature verification of chip cards argue that it will drive adoption faster than if consumers are required to memorize a PIN in order to pay with them.