3-20.1 Flashcards
Name some foundational infosec models
State machine, Non-Interference, Informational Flow
Name some Relationship, or higher level, models
Bell-LaPadula, Biba, Clark Wilson, Graham Denning, and Brewer/Nash
What is a state model?
Foundational model that ensures no matter what activity is taking place within a system, it is always trustworthy
What is a non-interference model?
Dictates that whatever happens at one security level doesn’t not directly or indirectly affect the security model of other levels.
What is the information flow model?
Focuses on controlling the information flow and ensuring it does not violate te security policy. Allows and prevents based on authorization.
What are the interactions between subject and objects in information security?
Subjects cause information to flow or change system state. Objects are passive entities that contain or receive information.
What is Bell-Padula?
Objective is confidentiality. No Read up, no write down. Simple Rule: Objects cannot read data whose classification is higher than their clearance. Subjects cannot write to an object at a lower classification than their clearance.
What is BIBA?
Objective is integrity (No read down - no write up). Simple Rule: Subjects cannot read data that has a lower classification than their clearance. Star Rule: Subjects cannot write to an object at a higher classification than their clearance level.
What is Clark-Wilson?
Objective is integrity. Well-formed transactions ensure that a user cannot alter data arbitrarily. Data can only be altered in a specific way in order to preserve it internal consistency (access triple).
→ Prevent unauthorized users from making modifications.
→ Prevent unauthorized users from making improper modifications.
→ Maintain internal and external consistency.
What is Sutherland?
Sutherland: Objective is integrity
→ Focuses on preventing interference.
Used to prevent a covert channel from being used to exploit a process or activity.
What is Brewer/Nash?
Objective is to defend against conflicts of interest.
→ Conflict of interest categories must be defined.
→ Access controls change dynamically depending upon a user’s previous action. Model is used in contexts where preventing conflicts of interest is critical, such as financial or legal environments. It provides a practical approach to controlling information flow and access based on the principle of maintaining separation between conflicting interests within an organization.
