Apple describes how to give authentication the finger

Patent application describes delivery of another identity factor just as cloud services make push for strong authentication.

In a patent application filing Thursday, Apple revealed the technological underpinning of fingerprint scanning technology the company could use as part of a next-generation authentication system for its phones, tablets and laptops.

There is widespread speculation that the iPhone 5S, which is expected to ship this fall, will include fingerprint-scanning technology.

Multi-factor authentication schemes are beginning to find favor with online services, but most rely on a code sent to a user's phone. Apple's biometric authentication via a fingerprint could be used independently or as part of a two-factor authentication.

CrucialTec earlier this year demonstrated a fingerprint scanner for mobile phones and Samsung is rumored to be developing the technology.

The newly formed Fast Identity Online (FIDO) Alliance, which is focused on strong authentication, lays out a finger sensor option that would be paired with protocols it is developing. FIDO has been tracking the newest iPhone and other fingerprint scanner developments with keen interest, as the Alliance would provide the plumbing for biometric authentication at scale for cloud-based services.

Apple's patent application describes a technology that would use the touchscreen along with an array of pixel sensors and electrodes under the screen, all of which fits within the rumored iPhone 5S design. The arrangement of the pixel sensors and electrodes would define the fingerprint sensor area on the phone's screen.

The technology described in the patent application comes via AuthenTec, which Apple acquired in 2012 for $365 million .

The application was authored by Dale Setlak, AuthenTec's former vice president of research and development.

Setlak lays out the design for a finger sensor with touch screen inputs. Setlak's design does not call for any input keys, but does say the fingerprint sensor could be used with portable or stationary electronic devices.

The design describes arrays of pixel sensors and electrodes to collect measurements. The design allows for a selection of measurement schemes that would allow 2-dimentional measurements, which are considered to be a more accurate read on the user's fingerprint.

Setlak also writes that electrodes used in gathering measurements could serve double-duty as touch sensing pixels when the fingerprint reading function is not in use.

The full draft of the patent applications is available at the US Patent and Trademark Office website.