Of the key new features introduced in the iPhone 5S, none appeared to have received as much attention as “Touch ID,” the finger print sensing component that is intuitively hidden inside the device’s home button. The idea of including such a technology, as explained by Apple’s Hardware Engineering Senior Vice President, Dan Riccio, is to ensure that an iPhone user’s privacy is fully protected and that various user-based transactions –for example, the ones performed on iTunes– can be implemented without any hassle. (An online app store purchase, just to illustrate, can now be completed by simply placing a finger on top of the iPhone’s home button, rather than manually inserting a password).
Not surprisingly, much of the strength of Apple’s fingerprint sensor has been attributed to its capacitance reader, which is generally perceived to be a more suitable –if not superior– option to traditional optical readers. The optical method mainly relies on using micro camera devices to capture as well as recognize the images of a person’s fingerprint. While relatively easy to implement, most optical fingerprint authentication systems end up being susceptible to various exploitation methods, among them the use of photocopied fingerprints and “fake fingers” that are made of gelatin (the kind of ingredient used to make gummy bears).
In the capacitance biometrics method, electric fields are generated to detect and assess the thickness differences in the dermal layers of a person’s finger, which is then used to piece together a detailed, highly sophisticated template of the fingerprint. Though the procedures involved tend to be relatively more complicated than the optical reader’s (involving a lot of encryption as well as algorithms, for example), a capacitance-based fingerprint sensor, according to Tidbits, is typically able to give off a more accurate reading, can recognize fingers even when they’re smudgy, and is not easily fooled by the use of photocopied or artificially created fingerprints. To ensure a higher level of security for its users, Apple, notably, has also made sure to store the finger print data inside the iPhone’s A7 chip rather than on its iCloud server or the internet.