Protecting your payments with Google Wallet
says. 'First, Google Wallet is protected by a PIN — as well as the phone’s lock screen, if a user sets that option. But sometimes users choose to disable important security mechanisms in order to gain system-level “root” access to their phone; we strongly discourage doing so if you plan to use Google Wallet because the product is not supported on rooted phones. That’s why in most cases, rooting your phone will cause your Google Wallet data to be automatically wiped from the device.'