Anybody reading this blog is undoubtably confused by the endless discussion of Apple Pay Suica errors and problems. Here is some explanation to help you understand them and how A12 Bionic in iPhone XS/XR solves them.
Apple Pay Suica problems are not problems with FeliCa technology. The problems are caused by the way Apple implements FeliCa technology on their hardware. Instead of a dedicated FeliCa chip from Sony (i.e. an independent hardware embedded secure element) Apple uses a custom embedded Secure Element with per device unique keys licensed from FeliCa Networks. While Apple’s custom implementation of FeliCa on the iPhone 7 through iPhone X is clever and cost-effective there are downsides:
- iOS has to babysit secure element transaction and be running for Apple Pay Suica to work. Japanese Android devices with dedicated FeliCa chips can still use Suica when the battery runs down and the OS is off.
- Different iOS versions affect Apple Pay Suica performance.
Apple Pay Suica Express Transit Mode Problems
Because iOS has to babysit secure element transaction, some iOS versions had better NFC performance than others:
- The iOS 10.1 Apple Pay Suica debut release worked pretty well but occasionally tripped up at transit gates, slamming them shut and forcing a re-read. By iOS 10.3 Apple Pay Suica performance was great.
- The Apple Pay Cash iOS 11.2 release made life miserable for all Apple Pay Suica users. Apple fixed it with the iOS 11.2.5 update.
And so on, bugs get fixed but major new iOS versions can introduce new bugs that affect NFC performance.
The A12 Bionic Difference
The great news is that A12 Bionic does away with this iOS Suica version by version, “iOS loves me, iOS loves me not” game. iPhone XR/XS have supercharged NFC thanks to the new A12 Bionic architecture and Secure Enclave that powers Express Cards with power reserve. Here is what we know so far:
- Apple Pay Suica Express cards with power reserve do transit, recharge and purchase without iOS running.
- The iOS Security Guide for iOS 12 shows the A12 Secure Enclave and Secure Element layer residing in the kernel/firmware layer that does not need iOS to be running, it also says “the NFC controller performs express card transactions under the same conditions as when iOS is running.”
The superior performance of Apple Pay Suica on iPhone XR/XS indicates that the A12 Secure Enclave and Secure Element layer load FeliCa keys and code and uses them not only in power reserve mode but also for regular mode completely removing all the iOS overhead and interaction for Suica transactions. This is how smartphones with a real FeliCa chip work, and now Apple has brought this power reserve functionality to Apple Silicon without a FeliCa chip. It’s a neat solution that makes iPhone XS Apple Pay Suica ‘bulletproof’ to any given iOS version.
It just works, even when the battery runs down.