Yesterday, an Apple patent application related to Touch ID detailing the circuits and packaging for fingerprint sensors was brought forward and today, the US Patent and Trademark Office has published a patent application from Apple that reveals the mechanics behind this “secure enclave” in the new A7 chip, where all the Touch ID fingerprint information is encrypted and stored (via PatentlyApple).
Apple states that the A7 chip includes an application processor and a secure enclave processor (SEP), each of which can include multiple processors, multiple cores, or reside on the same processor. The SEP can be specially and/or specifically designed and/or configured to perform encrypted tasks, such as encrypting data associated with an authorized user’s fingerprint. However, a potential drawback of the system is that the AP is partially unsecured, and certain fingerprint template maps may contain sufficient information for a thief to reverse engineer the template to construct a pattern that could unlock the device.
The filing details that in order overcome this potential security drawback, Apple’s invention includes a process of “collapsing the full maps into a sort of checksum, hash function, or histogram”.
“The exemplary pattern could include in each slot an average value over a respective vector of the map. The exemplary pattern could include in each slot a sum of the values over a respective vector of the map. The exemplary pattern could include the smallest or largest value within a respective vector of the map, or could be a difference between a largest and a smallest value within the respective vector of the map.”
Apple details numerous other exemplary embodiments. For more info regarding the patent filing, hit up this link.