During device initialization the user should be allowed to set a "security level". For any value other than the lowest security level firmware updates will have to have a correct digital signature. In a medium security level setting the signing key would bet set at initialization but could be changed later. At a high security level the signing key would be fixed for the lifetime of the device after initialization.
During device initialization the user should be allowed to set a "security level". For any value other than the lowest security level firmware updates will have to have a correct digital signature. In a medium security level setting the signing key would bet set at initialization but could be changed later. At a high security level the signing key would be fixed for the lifetime of the device after initialization.