A method for providing an anti-rollback secure timer service includes determining, at a device which includes a processor providing a trusted execution environment (TEE), a trusted memory, and a real time clock (RTC) accessible through an operating system of the device, an initial reference time value, by a secure timer application running in the TEE, the initial reference time value determined based on an initial value of the RTC obtained during booting of the device and a time delta value. The method further includes determining an updated reference time value based on the initial reference time value, a second value of the RTC, and a previously stored old reference time value, determining an updated time delta value based on the second value of the RTC and the updated reference time value, and storing the updated time delta value and the updated reference time value in the trusted memory.