A device including a NAND-flash memory comprising a read-only portion storing boot code and a key, and a system on a chip (SoC) coupled to the NAND-flash memory is provided. The SoC includes a read-only memory (ROM) storing one or more instructions and a processor configured to execute, upon startup, the one or more instructions stored in the ROM to request from the NAND-flash memory the boot code and the key. The processor further configured to load and execute the boot code to perform a chain of trust verification process on subsequent code during a booting process using the key. A method for using the device is also presented.