Rupanya A7 adalah kunci utama dari Touch ID. Apple sudah siap dengan teknologi sensor sidik jarinya, namun Apple masih butuh prosesor yang memiliki konsep enkripsi dan keamanan yang tinggi sehingga mampu menangani sistem pembayaran mobile dengan aman.

Via Quora:

There are numerous reasons Apple moved to the A7 processor. One reason is the hardware requirements of Touch ID. To economically create the Secure Enclave, Apple needed a processor that is already aware of the concept of encryption and security at a native level and has the dedicated hardware to make a segregated and secure area with in the processor architecture.