1. A security method comprising: (a) digitally signing a first load module with a first digital signature designating the first load module for use by a first device class; (b) digitally signing a second load module with a second digital signature different from the first digital signature, the second digital signature designating the second load module for use by a second device class having at least one of tamper resistance and security level different from the at least one of tamper resistance and security level of the first device class; (c) distributing the first load module for use by at least one device in the first device class; and (d) distributing the second load module for use by at least one device in the second device class.