Chapter 11 (Lecture 10) Flashcards
- Name at least seven security models.
1. Security models include state machine, information flow, noninterference, Take-Grant, access control matrix, Bell-LaPadula, Biba, Clark-Wilson, Brewer and Nash (aka Chinese Wall), Goguen-Meseguer, Sutherland, and Graham-Denning.
- Describe the primary components of TCB.
- The primary components of the trusted computing base (TCB) are the
hardware and software elements used to enforce the security policy (these elements are called the TCB), the
security perimeter distinguishing and separating TCB components from non-TCB components, and
the reference monitor that serves as an access control device across the security perimeter.
- What are the two primary rules or principles of the Bell-LaPadula security model? Also, what are the two rules of Biba?
- The two primary rules of Bell-LaPadula are the simple rule of no read up and the star rule of no write down. The two rules of Biba are the simple rule of no read down and the star rule of no write up.
- What is the difference between open and closed systems and open and closed source?
- An open system is one with published APIs that allow third parties to develop products to interact with it. A closed system is one that is proprietary with no third-party product support. Open source is a coding stance that allows others to view the source code of a program. Closed source is an opposing coding stance that keeps source code confidential.
- What is system certification?
A. Formal acceptance of a stated system configuration
B. A technical evaluation of each part of a computer system to assess its compliance with security standards
C. A functional evaluation of the manufacturer’s goals for each hardware and software component to meet integration standards
D. A manufacturer’s certificate stating that all components were installed and configured correctly
- B. A system certification is a technical evaluation. Option A describes system accreditation. Options C and D refer to manufacturer standards, not implementation standards.
- What is system accreditation?
A. Formal acceptance of a stated system configuration
B. A functional evaluation of the manufacturer’s goals for each hardware and software component to meet integration standards
C. Acceptance of test results that prove the computer system enforces the security policy
D. The process to specify secure communication between machines
- A. Accreditation is the formal acceptance process. Option B is not an appropriate answer because it addresses manufacturer standards. Options C and D are incorrect because there is no way to prove that a configuration enforces a security policy and accreditation does not entail secure communication specification.
- What is a closed system?
A. A system designed around final, or closed, standards
B. A system that includes industry standards
C. A proprietary system that uses unpublished protocols
D. Any machine that does not run Windows
- C. A closed system is one that uses largely proprietary or unpublished protocols and standards. Options A and D do not describe any particular systems, and Option B describes an open system.
- Which best describes a confined or constrained process?
A. A process that can run only for a limited time
B. A process that can run only during certain times of the day
C. A process that can access only certain memory locations
D. A process that controls access to an object
- C. A constrained process is one that can access only certain memory locations. Options A, B, and D do not describe a constrained process.
- What is an access object?
A. A resource a user or process wants to access
B. A user or process that wants to access a resource
C. A list of valid access rules
D. The sequence of valid access types
- A. An object is a resource a user or process want to access. Option A describes an access object.
- What is a security control?
A. A security component that stores attributes that describe an object
B. A document that lists all data classification types
C. A list of valid access rules
D. A mechanism that limits access to an object
- D. A control limits access to an object to protect it from misuse by unauthorized users.
- For what type of information system security accreditation are the applications and systems at a specific, self-contained location evaluated?
A. System accreditation
B. Site accreditation
C. Application accreditation
D. Type accreditation
- B. The applications and systems at a specific, self-contained location are evaluated for DITSCAP and NIACAP site accreditation.
- How many major categories do the TCSEC criteria define?
A. Two
B. Three
C. Four
D. Five
- C. TCSEC defines four major categories: category A is verified protection, category B is mandatory protection, category C is discretionary protection, and category D is minimal protection.
- What is a trusted computing base (TCB)?
A. Hosts on your network that support secure transmissions
B. The operating system kernel and device drivers
C. The combination of hardware, software, and controls that work together to enforce a security policy
D. The software and controls that certify a security policy
- C. The TCB is the combination of hardware, software, and controls that work together to enforce a security policy.
- What is a security perimeter? (Choose all that apply.)
A. The boundary of the physically secure area surrounding your system
B. The imaginary boundary that separates the TCB from the rest of the system
C. The network where your firewall resides
D. Any connections to your computer system
- A, B. Although the most correct answer in the context of this chapter is option B, option A is also a correct answer in the context of physical security.
- What part of the TCB concept validates access to every resource prior to granting the requested access?
A. TCB partition
B. Trusted library
C. Reference monitor
D. Security kernel
- C. The reference monitor validates access to every resource prior to granting the requested access. Option D, the security kernel, is the collection of TCB components that work together to implement the reference monitor functions. In other words, the security kernel is the implementation of the reference monitor concept. Options A and B are not valid TCB concept components.