An apparatus, comprising: - a non-secure zone; - a secure zone coupled to the non-secure zone via an interface, wherein the secure zone is configured to receive a task having one or more subtasks from the non-secure zone via the interface, and wherein the secure zone is further configured to: - execute the task having one or more subtasks, wherein the task and the subtasks have respective executable code for one or more secure transactions, the task and the subtasks are digitally signed by respective code providers, and execution is switched between the task and at least one subtask of the one or more subtasks; and - apply respective sets of permissions describing access to certain portions of the secure zone while the respective executable code of the task and a subtask are executed, wherein the respective set of permissions for the task are 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, and wherein the respective set of permissions for the subtasks are based on at least one of information associated with the signed subtasks and information in a digital certificate of the respective code provider for the subtasks. - a non-secure zone; - a secure zone coupled to the non-secure zone via an interface, wherein the secure zone is configured to receive a task having one or more subtasks from the non-secure zone via the interface, and wherein the secure zone is further configured to: - execute the task having one or more subtasks, wherein the task and the subtasks have respective executable code for one or more secure transactions, the task and the subtasks are digitally signed by respective code providers, and execution is switched between the task and at least one subtask of the one or more subtasks; and - apply respective sets of permissions describing access to certain portions of the secure zone while the respective executable code of the task and a subtask are executed, wherein the respective set of permissions for the task are 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, and wherein the respective set of permissions for the subtasks are based on at least one of information associated with the signed subtasks and information in a digital certificate of the respective code provider for the subtasks. - execute the task having one or more subtasks, wherein the task and the subtasks have respective executable code for one or more secure transactions, the task and the subtasks are digitally signed by respective code providers, and execution is switched between the task and at least one subtask of the one or more subtasks; and - apply respective sets of permissions describing access to certain portions of the secure zone while the respective executable code of the task and a subtask are executed, wherein the respective set of permissions for the task are 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, and wherein the respective set of permissions for the subtasks are based on at least one of information associated with the signed subtasks and information in a digital certificate of the respective code provider for the subtasks.