Paper 2 Flashcards
Operating system functions/purpose
(Processor, Memory, Application, Security) management
User/hardware interface
How do interpreters work
No machine code
Call MC subroutines to carry out commands
Translation line by line
Stops when error found
Why is there more RAM than cache
Ram is cheaper
Cache can’t store data and programs simultaneously
Issues with SSDs
Expensive
Low storage capacities
Limited rewrite capacity
Sample resolution
No. Of bits/ sample
WAN v LAN
WAN operates over larger area
WAN has morre devices connected
WANs are slower than LANs
WANs have collective ownership
Wireless over wired networks
Easier to add new devices
No tripping hazards
Less cable management/issues
Easy guest access
Reasons for automatic software updates
People forget to update manually
Computers get protected faster
Updates from trusted sources
When is RLE not useful
Few repeated characters
RLE takes up more space than the original file
“Relational database”
A database with multiple tables that are linked together
Benefits of relational databases
Reduces redundancy/inconsistencies over databases
Unicode > ASCII
More available characters
Different languages
Technical characters
SSD benefits
More portable
Use less power
Generate less heat
Data read from magnetic disc
Read head is moved
Disk spins around
Whole sector read in one go
Polarisation reflects 1/0
Advantages of cloud storage
Access data from several devices
Easily share data
Increase available storage
Reasons for growth in cloud storage
Higher bandwidth mobile networks
Increase in mobile devices
Better network security
Trust in 3rd parties
Advantages of computer networks
Easy To transfer data
Increased available storage
Computer usage monitoring
Central management/backups
Blagging
Victim persuaded to give details for a false purpose
(Nigerian prince)
Phishing
Victim thinks they’re communicating with a trusted source - is in fact fraudulent
Shouldering
Credentials being watched/recorded when being typed
High level language > low level language
Built in functions/libraries
Easier to write/debug/understand
Require fewer lines
easier to structure
When is MAC filtering not useful
Wireless network open to the public
MAC address of connected devices won’t be known
Function vs procedure
Procedure accepts arguments but doesn’t return values
Function returns one or more values
OS managing Input/Output devices
Downloads drivers
Allows data to be sent/received
OS managing security
User authentication
Malware protection
Blocking access to vulnerable parts of a system
OS managing processors
Scheduling programs to be executed
OS managing storage
Secondary data management
Efficient space allocation
Identity method confirmation
Passwords - only the user would know/checked against database
Biometrics - physical features
Email confirmation - only valid email proves identity
Black box pen. testing
No understanding of how system works
Mimics external hacker
Discovery & exploitation of weak spots
White box pen. testing
Understanding of system
Mimics malicious insider
Testing specific vulnerabilities
Go through all scenarios
Spyware
Records data on host system
Sends to 3rd party
Trojan malware
Misleads user - think its a different piece of software
Executes other program
Worm
Autonomous self replication on a host system
Ransomware
Encrypts data until decryption key is paid for
Keyloggers
Monitors keystrokes to find and steal passwords for confidential purposes
Password weaknesses
Short, potentially blank
No mixture of letters, numbers, and symbols
Ordered numbers/easily guessable
Disadvantages of cloud storage
Increased security risks
Reliance on providers
Increasing costs
Data leaks
