A12 Bionic Bulletproofed Apple Pay Suica

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 and iPhone 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 using a real FeliCa chip from Sony, Apple created a virtual FeliCa chip on the A-Series chip with per device unique keys licensed from FeliCa Networks.

Apple’s custom implementation of FeliCa on the Apple Pay platform is clever and cost-effective in many ways but there are downsides:

  • iOS/watch OS has to be running for Apple Pay Suica to work. Japanese Android devices with FeliCa chips can still use Suica when the battery runs down.
  • Different iOS/watchOS versions affect Apple Pay Suica performance in good ways, and bad ways.

Apple Pay Suica Software Problems
Wireless radio technology like NFC, WiFi, Bluetooth and cellular is a delicate balance of software and hardware that often seems like a black art. A small code tweak or tiniest hardware flaw can easily upset the balance and wreak havoc. Remember the ‘you’re holding it wrong’ iPhone 4 anntenagate crisis? Like that.

Occasional iOS versions have caused Apple Pay Suica performance problems:

  • 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.

It’s happening again with the iOS 12/iOS 5 debut release. iPhone 8, Revision B iPhone X, Apple Watch 3/4 users are experiencing unresponsive Express Cards and Apple Pay demanding a Passcode/Face ID unlock at transit gates, or just good old error flicker (Suica error correction algorithms on JR East transit gates are truly amazing BTW). I’m sure Apple iOS engineers are on it and Apple Pay Suica performance will be back to normal after an update or two.

Express Card Power Reserve Mode
Express Card power reserve mode on iPhone XS and iPhone XR lasts up to 5 hours. You can use it for transit, recharge and purchase.

The A12 Bionic Difference
This kind of Suica, “iOS loves me, iOS loves me not” version by version game is a consequence of Apple requiring iOS to operate Suica on pre-A12 Bionic devices. iPhone XS users are not having Suica problems with iOS 12 thanks to the new A12 Bionic architecture and Secure Enclave that powers Express Cards with power reserve. Here is what we know so far:

If I had to take a guess from the superior performance of Apple Pay Suica on iPhone XS, the A12 Secure Enclave and Secure Element layer loads FeliCa keys and code and uses them not only in power reserve mode but also for regular mode Express card operation completely removing all the iOS overhead and interaction for basic Suica operations. It is much closer to how a Suica smartcard works. This makes iPhone XS Apple Pay Suica ‘bulletproof’ to any given iOS version. It just works, even when the battery runs down.

Apple Watch Series 4 still uses the ‘OS has to be running scheme’ as the Apple S4 does not support Express Cards with power reserve. I think the Apple Chip design team must be working on a S-Series chip that will have the same features of the A12 Bionic Secure Enclave and Secure Element architecture. Express Cards with power reserve and bulletproof Suica will be a great selling points for Apple Watch in Japan when it arrives.

Most of this explanation is about FeliCa and Apple Pay Suica but the same methods can be used for all other middleware stacks: Express Cards with power reserve work with Apple Pay Transit in China.

The iPhone X Suica Problem
Last but not least there is the iPhone X Suica problem which I have covered extensively over the past year. This is a completely different beast from all of the above, a unique and rare Apple failure unrelated to iOS or A-Series Secure Enclave architecture. The iPhone X Suica problem is a NFC hardware problem with iPhone X units manufactured before April 2018 and is fixed in Revision B iPhone X units manufactured after that date. Exchanging a problem iPhone X unit is the only way to resolve the problem. Unfortunately Apple is making exchanges very difficult for iPhone X customers with problem devices who need help. I hope Apple will come its senses and issue a repair program for iPhone X customers who really need Apple’s help.

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