Quiz 10 Flashcards
What does the principle of economy of mechanism states?
Security mechanisms should have limited monetary cost
Security should only be deployed if absolutely necessary
Security mechanisms should be as simple as possible (as long as they get the job done)
This principle does not exist
Security mechanisms should be as simple as possible (as long as they get the job done)
What are the security-related goals typically considered in OS design?
Integrity, Availability, Confidentiality
What does the principle of least privilege states?
An OS should only define two users, and administrator and a regular user
No file in storage should be executable
A user password should not be longer than 16 characters
A process should only receive the minimum privileges necessary to perform its actions
A process should only receive the minimum privileges necessary to perform its actions
An OS may decide if a process is allowed to perform a certain action based on a security policy
True
Match authentication concepts to their definition
____
A computing entity performing a request for access on behalf of another party
____
A party (typically a human) that can request access to resources
- Principal
- Agent
__2__
A computing entity performing a request for access on behalf of another party
__1__
A party (typically a human) that can request access to resources
Passwords are examples of authentication based on “what you are”
True False
False
The “non-repudation” property means that if someone performs an action, they cannot deny that that action was performed
(True or False)
True
What is a false positive in the context of biometric authentication?
Determining that the user fingerprint has changed
Needlessly requiring 2-factor authentication
Refusing to let the right user into the system
Letting the wrong user into the system
Letting the wrong user into the system
Which I/O approach is more common in modern hardware peripherals?
Virtual address translation
Memory-mapped I/O
I/O using dedicated hardware instructions
Scheduled I/O
Memory-mapped I/O
What’s the role of a driver?
Enable the OS to interface with an hardware peripheral
Enable an hardware peripheral to communicate with the user
Enable user-space processes to interface with the OS
Enable user-space processes to interface with an hardware peripheral
Enable the OS to interface with an hardware peripheral
in and out X86 instructions allow to perform input/output using a dedicated I/O address space. (True or False)
True
The majority of code in modern OS’es is found in device drivers
True False
True
Interrupt-based I/O is always preferable to polling-based I/O
True False
False
Match the I/O strategy with the correct description
____
Repeatedly check whether I/O events have occurred
____
Asynchronously get notified when I/O events occur
- Polling-based I/O
- Interrupt-driven I/O
__1__
Repeatedly check whether I/O events have occurred
__2__
Asynchronously get notified when I/O events occur
Select all facts that apply to DMA
DMA is only used for GPUs
DMA allows I/O data to be moved between devices and memory with limited CPU involvement
DMA stands for Direct Mapping Access
DMA requires a dedicated controller
DMA allows I/O data to be moved between devices and memory with limited CPU involvement
DMA requires a dedicated controller
