With this system, the raw biometric information is never accessible to any software or system outside the module, including the phone’s own operating system. On the iPhone, this is called the secure enclave and is available on every phone with an Apple A7 chip or newer. The first phone with this technology was the iPhone 5S, released in 2013. Similar technology is also available on Android phones. Samsung, for example, started rolling out the ARM TrustZone trusted execution environment with the Samsung S3 smartphone.

Today, smartphone hardware security modules are used to provide security for Apple Pay, Google Pay and Samsung Pay as well as to authenticate third-party applications. PayPal, for example, can use a phone’s biometric sensor for authentication without PayPal ever seeing the actual biometric data itself. Square Cash, Venmo, Dropbox and many banking apps and password management apps leverage this authentication mechanism as well.

Enterprises can also use smartphone-based biometric readers whenever their users or customers have access to smartphones, without ever having to collect and store any identifying biometric information on their own servers. Similar technology is available for other types of devices, such as smart cards, smart door locks, or fingerprint scanners for PCs.

Smartphone-based authentication offers significant usability benefits. First, users tend to be immediately aware if they have misplaced or lost their smartphone and will take immediate steps to find or replace it. If, however, they misplace a badge that they only use to access a building during the off-hours, they might not notice for a while that it is missing.