Question

1. Suppose that some operating system (OS) implements the Biba integrity model in its original form (i.e., as described in the lectures). Also, supposed that there are only two integrity levels: “High” (for the system itself and the superuser) and “Low” for the ordinary users. Describe what issues the ordinary users may have with working on this OS?

Hint: Answer the following question: Will such the system run programs compiled by the ordinary users? (Explain your answer.) Specifically, what rule will be used to allow or deny it?

Answer 1

BIBA INTEGRITY MODEL :

The BIBA INTEGRITY MODEL works based on a hierarchical model that thinks about the honesty levels that are related with records, cycles, and individuals.

These integrity model uses three properties for protecting system objects from modifying illegally:

1 . Straightforward - INTEGRITY : These property is likewise called "no read down " and it states subjects at one uprightness level isn't allowed to peruse subject at a lower trustworthiness level .

2 . STAR - INTEGRITY : These property is additionally called " no review " and it states subjects at one honesty level isn't allowed to compose subject at a higher respectability level .

3 .INVOCATION : It expresses a subject at one respectability level isn't permmited for conjuring or calling a subject at a higher honesty level .

Clarification : When a "low" level client attempt to execute a program on this framework , the "high" level framework can't get to the low-level executable. Consequently "low" level can't execute a program. This is legitimized by the "Star-honesty" and "conjuring" properties of the Biba Integrity Model.