i guess it would be both .. that's why we are able to "read' the balance of the tng card from smart tag .. when u by pass the smart tag lane... system will sync with their office db on ur balance...
i think there was recent case user using mobile apps to bypass it.... no confirmation from tng company yet .. saying they are still investigating.. but if u are hardworking enuf.. u will see there was actually a case many years back ... few people kena nabbed coz they were able to edit the credit balance of tng ...
too bad, the tech. din pass to /k/ still T.T