An access control method for accessing an embedded system includes: performing a first access control operation for an access system by a first authentication subject, wherein the first access control operation includes performing a first authentication for the access system; when the first access control operation is passed, receiving at the first authentication subject a result of a second access control operation for the access system which is performed by a second authentication subject that is separate from the first authentication subject performing a second authentication for authenticating whether the access system is an access system that is authenticated by a second authentication subject that is separate from the first authentication subject, and receiving the result of the authentication; and allowing the access system to access the embedded system if the first authentication and the second authentication are successful.