Dynamic Rights in Model-Carrying Code

We consider safety mechanisms for mobile code, especially Model-Carrying Code (MCC) approach. We find that in many cases the MCC approach is superior over Proof-Carrying Code (PCC), since in many contexts the code safety deals with quantity and other dynamic issues, and proving such properties in general with static PCC is not possible. For example, in mobile phone context, one can prove with PCC that no SMS messages are sent, but in general it is impossible to prove with PCC that at most x SMS messages are sent. Guarding such properties at runtime with MCC is possible. We study mobile code safety requirements in workstation, web, mobile phone, and digital TV contexts by considering various use cases.