Domain 3: Security Architecture and Engineering - Security Models
6 important questions on Domain 3: Security Architecture and Engineering - Security Models
What is the purpose of a Security Model?
- Determine how security will be implemented, what subjects can access the system, and what objects they will have access to.
What are the properties of Security Models?
- Simple security property: Describes rules for read
- Star * security property: Describes rules for write
- Invocation property: Rules around invocations (calls), such as to subjects
What Security Models are about Integrity?
- Biba
State machine model (SMM) - Clark-Wilson
Access control triple - Goguen-Meseguer
THE noninterference model - Sutherland
preventing interference (information flow and SMM)
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
What Security Models are about Confidentiality?
- Bell-LaPadula -> government (DoD)
No read up, no write down
- Brewer and Nash
aka “Chinese Wall”
- Take Grant
Employs a “directed graph”
What is the definition of a State Machine Model?
- Describes a system that is always secure no matter what state it is in.
- Based on the computer science definition of a finite state machine (FSM).
- A state is a snapshot of a system at a specific moment in time. All state transitions must be evaluated.
- If each possible state transition results in another secure state, the system can be called a secure state machine.
What is the definition of an Information Flow Model?
- Focuses on the flow of information
- Information flow models are based on a state machine model
- Biba and Bell-LaPadula are both information flow models
- Bell-LaPadula preventing information flow from a high security level to a low security level
- Biba focuses on flow from low to high security level
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
![Trustpilot Logo](/images/design_2020/lp/clp-trustpilot-en.png)