Google may have stepped on the toes of a few Android “power users” — i.e., those who root and ROM their devices — when they decided to exclude rooted devices (along with everyone outside the US) from joining in on the mobile payment party. The part that rustled feathers was the fact that, before Android Pay was introduced, Google Wallet was handling mobile payments just fine and played nice with all NFC-equipped Android devices whether you were stock, rooted, or running a custom ROM. So why not Android Pay?
Shedding some light on the whole situation is Google security engineer Jason Clinton, who took to XDA the reasoning behind this decision and simply put — it’s all about security. While Google is committed to keeping Android open and developer-friendly, “there are a handful of applications (that are not part of the platform) where we have to ensure that the security model of Android is intact.” Android Pay uses Google’s SafetyNet API to check compatibility with verified devices upon installation. That means devices that have passed Android compatibility testing. Remember, mobile payments on Android Pay are handled much differently from when they were available on Google Wallet.
In Google Wallet, Google created virtual credit cards, acting as a sort of middle-man in the transaction process between the bank and merchant. In other words, all the risk was taken on and assumed by Google. Because Android Pay uses tokens to pass your actual card information to merchants, Google has to work directly with payment networks and banks (listed above) in order for Android Pay to work. To put it plainly, the banks are the ones with all the power here. If they’re not on board, Android Pay dies.
As you can see, there’s a lot that goes on behind the scenes and it’s almost silly to think that Google dropped root support on a whim without considering all the variables before hand. Clinton leaves the thread by saying that Google appreciates the dev community and will continue monitoring the thread for constructive ideas. Feel free to drop them a line in the XDA thread right here.