Biba Integrity Model

The Biba Integrity Model was developed to circumvent a weakness in the Bell La Padula computer operating system protection model which did not include the possibility of implicit deletion of security objects by writing to them.

In general, preservation of integrity has three goals:

Prevent data modification by unauthorized parties

Prevent unauthorized data modification by authorized parties

Maintain internal and external consistency (i.e. data reflects the real world)

The Biba model implements protection by defining an ordered series of integrity levels for subjects and objects, and enforcing a read-up and write-down rule:

This means that a subject at a given integrity level X can only read objects at the same or higher integrity levels - the simple integrity axiom .

Similarly a subject at integrity level X can only write objects at the same or lower integrity levels - the * (star) integrity axiom .

A subject at integrity level X can only invoke a subject at the same or lower integrity levels.

= See also =

Clark-Wilson model based on transactions.

Sutherland model that focuses on the problem of inference.

= References =

Original Paper: Biba, K. J.: Integrity Considerations for Secure Computer Systems, Technical Report MTR-3153, MITRE Corporation, Bedford, Massachusetts, April 1977.