An apparatus according to the present disclosure may comprise a secure zone configured to execute a task having a subtask. The task and subtask may have respective executable code and may be digitally signed by respective code providers. The secure zone may be further configured to apply respective sets of permissions while the respective executable code of the task and subtask are executed. The respective set of permissions for the task may be based on at least one of information associated with the signed task and information in a digital certificate of the respective code provider for the task. The respective set of permissions for the subtask may be based on at least one of information associated with the signed subtask and information in a digital certificate of the respective code provider for the subtask.