Domain 5: Security Architecture and Design Flashcards
What is RAM?
RAM (Random Access Memory): Volatile hardware memory that loses integrity after loss of power.
What is aReference Monitor?
Reference Monitor: Mediates all access between subjects and objects.
What is ROM?
ROM (Read Only Memory): Nonvolatile memory that maintains integrity after loss of power.
What is TCSEC?
TCSEC (Trusted Computer System Evaluation Criteria): Known as the Orange Book.
What is TCB?
TCB (Trusted Computer Base): The security relevant portions of a computer system.
What is Virtualization?
Virtualization: An interface between computer hardware and the operating system that allows multiple guest operating systems to run on one host computer.
What are the two things that Security Architecture and Design describes?
1: fundamental logical hardware, operating system and software security components
2: How to use those components to design, architect and evaluate secure computer systems.
What are the three Domain Parts to Security Architecture and Design describes?
1: Hardware and software required to have secure computer system
2: Logical models required to keep the computer secure
3: Evaluation models that quantify how secure a system really is
What does
Secure System Design represent?
universal best practices; It transcends specific hardware and software implementations.
What is layering?
Separates hardware and software functionality into modular tiers.
What networking protocol isi similar to layering by profiding a similar function?
TCP/IP
Explain how layeriing works when in your systej when you change disk drives from IDE to SCSI
Example: A disk drive in the hardware layer has changed from IDE to SCSI. The device drivers in the adjoining layer will also change but the other layers in the Operating System and the Application layers will remain unchanged.
What are the generic names for the four layers?
1: Hardware
2: kernel and device drivers
3: Operating System
4: Applications
Why is abstraction a good design principal?
Complexity is the enemy to security and computers are extremely complex machines.
Why does abstraction provide the user?
Abstraction hides unnecessary detail from the user and provides a way to manage that complexity.
In the context of Secure System Design Concepts, Name two definitions for a a Securitiy Domain?
1: A list of objects a subject is allowed to access.
2: Groups of subjects and objects with similar security requirements like CONFIDENTIAL, SECRET and TOP Secret or User Mode and kernel Mode.
What does kernel mode provide access to?
Allows low-level access to hardware (memory, CPU, disk, etc).
Most trusted and powerful part of the system.
What is another name for does kernel mode ?
Supervisor Mode
What is The Ring Model?
A form of CPU layering that separates and protects domains from each other.
What are the four generic names to the the Ring Model layers?
Ring 0: Kernel
Ring 1: Other OS components that do not fit into Ring 0
Ring 2: Device Drivers
Ring3: User Applications
What is the name for the process for communicting between layers in the Ring Model?
System Calls
What is one advantage and one disadvantage to System Calls?
System Calls are slow compared to inner ring communication but provide security.
Practically, why do most X86 CPUs, including Linux and Windows, only use Ring 0 and Ring 3
because of performance issues.
What Ring Layer does a Hypervisor operate in?
Hypervisor (Ring 1)
Allows virtual guests to operate in Ring 0.