Embedded system with authentication, and associated authentication method

An authentication method of an embedded system, comprising:

• providing a system read only memory (ROM), a processing circuit and an authentication circuit;
• utilizing the system ROM to store a boot code;
• utilizing the processing circuit to process at least according to the boot code in order to perform operations of the embedded system;
• and
• utilizing the authentication circuit to perform authentication on a command script in order to determine whether the command script is authenticated, and prevent the command script from being executed by the processing circuit when the authentication circuit determines that the command script is not authenticated, wherein the command script is received from outside a chip where the system ROM, the processing circuit and the authentication circuit are positioned;
• wherein the embedded system further comprises a serial port;
• and the authentication method further comprises:
• when the authentication circuit determines that the command script is not authenticated, utilizing the authentication circuit to trigger the embedded system to download a program code from a host outside the chip through the serial port, and utilizing the processing circuit to perform authentication on the program code according to the boot code.