Bad news, power-users: if you habitually root every smartphone you put in your pocket, you won't be able to use Samsung Pay. Users participating in the South Korean trial program have learned that devices with unrestricted access to the file system have been blocked from using the service. "Access denied," reads the app's error message. "Samsung Pay has been locked due to an unauthorized modification."
The restriction is an absolute bummer, particularly in light of the fact that Google Wallet doesn't mind root at all. To be fair, Samsung Pay is a little more complicated -- it makes uses MST (magnetic secure transmission) technology to trick older pay terminals into thinking a traditional credit card swept through its magnetic strip. This makes Samsung Pay more versatile than NFC-only payment solutions, but also adds a new vulnerability.
The company seems to be playing it safe for now. With any luck, Samsung will lift the restriction before the service launches world wide.