How Labels Are Used in Access Control Decisions

MAC compares the label of the process that is running an application with the label or the label range of any object that the process tries to access. MAC permits a process to read down to a lower label and permits a process to write to an equal label.

Label[Process] >= Label[Object]

A process bound to a multilevel port (MLP) can listen for requests at multiple labels and send replies to the originator of the request. In Trusted Extensions, such replies are write-equal.

Label[Process] = Label[Object]