1. A document security system for restricting access to documents, said document security system comprising: at least one process-driven security policy that includes a plurality of states and transition rules, each of the states having corresponding one or more access restrictions, and the transition rules specify when the secured document is to transition from one state to another; and an access manager that determines whether access to a secured document is permitted by a requestor based on the state and the corresponding one or more access restrictions thereof for said process-driven security policy.