Secure state
From Wikipedia, the free encyclopedia
A secure state is Information System security term to describe where entities in an computer system are divided into subjects and objects, and it can be formally proven that each state transition preserves security by moving from one secure state to another secure state. Thereby it can be inductively proven that the system is secure. As defined in the Bell-LaPadula model, the secure state is built on the concept of a state machine with a set of allowable states in a system. The transition from one state to another state is defined by transition functions.
A system state is defined to be "secure" if the only permitted access modes of subjects to objects are in accordance with a security policy. To determine whether a specific access mode is allowed, the clearance of a subject is compared to the classification of the object to determine if the subject is authorized for the specific access mode. The clearance/classification scheme is expressed in terms of a lattice of access control rules.
