Security Models Flashcards
Confinement
Process confinement restricts the actions of a program. Process confinement allows a process to read from and write to only certain memory locations and resources. This is also known as sandboxing.
Bounds
Each process that runs on a system is assigned an authority level. The authority level tells the operating system what the process can do. There may only be two authority levels: user and kernel.
Isolation
When a process is confined through enforcing access bounds, that process runs in isolation. Process isolation ensures that that any behavior will affect only the memory and resources associated with the isolated process. Isolation is used to protect the operating environment, the kernel of the OS, and other independent applications.
Trusted System
A system in which all protection mechanisms work together to process sensitive data for many types of users while maintaining a stable and secure computing environment.
Assurance
Defined as a the degree of confidence in satisfaction of security needs. Assurance must continually be maintained, updated, and reverified.
Trusted Computing Base
A combination of hardware, software, and controls that work together to form a trusted base to enforce your security policy.
State Machine Model
A mathematical model that groups all possible system occurrences, called states. Every possible state of a system is evaluated, showing all possible interactions between subjects and objects. If every state is proven to be secure, the system is proven to be secure.
Information Flow Model
Describes how information may flow in a secure system.
Bell-LaPadula and Biba use the information flow model.
Noninterference Model
Ensures that data at different security domains remain separate from one another.
Implementing this model assures that covert channel communication does not occur.
Take-Grant Model
Contains rules that govern the interaction between subjects and objects, and permissions subjects can grant to other subjects.
Rules include: take, grant, create and remove.
Access Control Matrix
A table that defines access permissions.
Bell-LaPadula Model
Originally developed for the DoD.
Focused on maintaining the confidentiality of objects.
No read up, no write down.
Biba Model
Focused on maintaining integrity.
No read down, no write up.
Clark-Wilson Model
Protects integrity by requiring subjects to access objects via programs.
Uses two primary concepts to ensure that security is enforced: well-formed transactions and Separation of Duties.
Goguen-Meseguer Model
Foundation of noninterference conceptual theories.
