Apple patent filing outlines how NFC-based mobile payments work

BY Joe Rossignol

Published 9 Oct 2014

Apple Pay

Apple is set to make a big splash into the mobile payments industry with Apple Pay when the service launches this month, although details surrounding the platform have remained fairly limited until now. The U.S. Patent and Trademark Office on Thursday published an Apple patent application that sheds some additional light on how NFC-based mobile payments work in conjunction with secure enclaves and software for safe transactions.

The comprehensive patent filing, officially titled “Methods for Adjusting Near Field Communications Circuitry during Mobile Payment Transactions,” provides a detailed look at how an electronic device equipped with an NFC module, like the iPhone 6 and iPhone 6 Plus, can automatically detect the electromagnetic field of a nearby point-of-sale system, such as those commonly found at check outs or drive-thru windows.

When an NFC-compatible device is within the field of and securely authenticated with a point-of-sale system, the terminal can then securely transfer user credentials and tokenized payment data based on various encryption methods. The patent shares an illustration that details how the merchant payment processor can connect to a payment network subsystem to verify and log transactions.

AppleInsider further explains the technical intricacies of this exhaustive patent filing:

“As for payment credentials, such as credit card or stored-value card information, the system meshes software and hardware encryption for secure input and storage. In some cases, a user connects to a service provider subsystem to provision new cards onto their device. A broker module on the user device side takes care of authentication with payment network subsystems and manages credentials, while a trusted service manager (TSM) handles secure interaction with POS terminals.

Using this technique, the system is able to remotely authorize secondary user devices to download card provisions. Apple already announced the forthcoming Apple Watch will be Apple Pay-compatible and the patent confirms support for a secure enclave on accessories, mentioning a wristwatch as an example. These secondary devices do not necessarily require the same cellular connectivity as the originally provisioned device, but can instead perform a subset of payment functions as long as a secure enclave is present.”

These security measures and tokenized payment data help make Apple Pay safe for the over 800 million iTunes customers with credit cards on file that may wish to use the service. If a thief was able to intercept the data during transmission, it would be useless because of the unique digital tokens that can only be decoded by compatible point-of-sale systems using a shared secret method.

The patent filing goes into extensive detail about several other areas of NFC-based payment technologies, including how an iPhone or other device can automatically attempt to reconnect to a point-of-sale system within a predetermined amount of time if there are multiple unsuccessful payment attempts. If the payment device falls out of range of the terminal, it will temporarily save the device’s details in case a connection is reestablished.

Apple was given United States Patent Application No. 20140304094.