Chapters 7-8 Flashcards
Host, endpoint
A computing device
Client
Intermittent connection, requests services
Server
Stable connection, waits for service requests
Core
Routers and switches
Middle boxes
Firewalls, NATs, VPNs
Protocol
Set of rules/standards that govern an interaction
TCP
Reliable, has ordered delivery, congestion and flow control. Sets up a connection.
UDP
Unreliable, unordered delivery, connectionless
DHCP
Dynamically assigns IP addresses when a host enters a subnet
Parity bit
A bit which serves to detect and sometimes correct bit errors
Reason why signal gets exponentially weaker the further away from the source
Inverse Square Law
Infrastructure mode
All devices connect to a central access point
Ad-hoc mode
Devices communicate directly with each other. There is no central access point
Mesh Network
A combination of both Infrastructure and Ad-hoc, devices self-organize to relay messages, with each device serving as a router and/or switch for the other devices that it can hear
CSMA-CA
Listens before transmitting, requests to transmit, receives permission, transmits, receives ACK from access point
Passive scanning
listens for beacon frames from access points, beacon frame includes the SSID of the access point
Active scanning
Device sends a request for points to identify themselves
Association Process
Device sends association request frame to specific AP, selected AP sends association response frame, the DHCP usually happens
4G and 5G
IP cores
CIA triad
Confidentiality, Integrity, Availiability
Confidentiality
Only authorized persons should be able to access system
Integrity
Only authorized persons should be able to modify data
Availability
System needs to be accessible when needed
Substitution cipher
Uses confusion
Transposition cipher
Uses diffusion
Stream cipher
Operates on one bit at a time, can only use confusion
Block cipher
Operates on blocks of bits, normally described based on the size of the block on which it operates
Symmetric key cipher
The same key is used for encryption and decryption
Asymmetric key cipher
Two related keys, one for encryption and the related key for decryption
Brute-Force Attack
Systematically trying every possible key until you find the correct one
Break
Any attack that is more efficient than a brute-force attack
Checksums
Produce fixed-size output no matter the input size, used to detect transmission errors
SSL
Broken security protocol, do not use
TLS
Transport layer security, provides confidentiality, integrity, and authentication
IPSEC
Network layer, provides confidentiality, integrity, and authentication. Used in VPNs
WEP
Broken wifi security protocol, do not use
WPA 2 and 3
WiFi security Protocols which are good