Wireless

Question 1

Ad Hoc

Answer 1

Wireless devices communicate directly with each other without centralized access point
-Peer to peer

Question 2

Infrastructure

Answer 2

-wireless devices communicate through router or access point
-more traditional

Question 3

IBSS

Answer 3

-Independent Basic Service Set
-contains only devices/clients with no APs (AD-HOC WLAN)

Question 4

BSS

Answer 4

Basic Service Set
-Only one AP connected to the network (SOHO network)

Question 5

ESS

Answer 5

Extended service set
-contains multiple APs to provide coverage (College campus)

Question 6

Direct-Sequence Spread Spectrum (DSSS)

Answer 6

-modulates data over an entire range of frequencies using a series of signals known as chips
-more susceptible to environmental interference
-uses entire frequency spectrum to transmit

Question 7

Frequency-Hopping Spread Spectrum (FHSS)

Answer 7

-devices hops between predetermined frequencies
-increases security as hops occur based on a common timer

Question 8

Orthogonal Frequency Division Multiplexing (OFDM)

Answer 8

-uses slow modulation rate with simultaneous transmission of data over 52 data streams
-allows for higher data rates while resisting interference between data streams
-channel bonding

Question 9

CSMA/CA

Answer 9

Carrier Sense Multiple Access/Collision Avoidance
-can be wired or wireless
-the act of a node listening before they transmit
-wlan used to control access to medium
-listens before transmitting
-sends Request to Send (RTS)
-waits for acknowledgement
-if receives a RTS, responds with Clear to Send(CTS)
-if not received, uses random back off timer

Question 10

Pre-Shared Key

Answer 10

-both AP and client share same encryption key
-problems:
—scaling is difficult if key is compromised
—all clients must know same password

Question 11

Wired Equivalent Privacy (WEP)

Answer 11

-uses RC4 encryption protocol
-original wireless security standard (claimed to be as secure as wired network)
-static 40-bit pre-shared encryption key (upgraded to 64 and 128-bit)
-uses 24-bit initialization vector sent in clear text

Question 12

Wi-Fi Protected Access (WPA)

Answer 12

-uses TKIP encryption protocol
-Temporal Key Integrity Protocol (TKIP)
—48-bit initialization vector
-uses Message Integrity Check (MIC)
—confirms data not modified in transit
-Enterprise WPA
—users can be required to authenticate before joining network
—keys between client and ap are temporary

Question 13

WPA2

Answer 13

-uses AES encryption protocol
-Integrity checking through CCMP (Counter Mode Cipher Block Chaining Message Authentication Code Protocol)

Question 14

WPS

Answer 14

WiFi Protected Setup
-involves pressing down WPS button to pair to router (8 digit pin)
-unsecured to brute force attacks
-doesn’t work with WEP

Question 15

CSMA/CD

Answer 15

Carrier Sense Multiple Access / Collision Detection
-can be wired or wireless
-defines the method for detecting a collision.
-used by wired Ethernet to control access to medium
-listens, verify it’s not busy (carrier sense)
-all devices have access at same time (multiple access)
-if collision occurs use back up timer(collision detect)

Question 16

CCMP

Answer 16

Counter mode with cipher block chaining message authentication protocol
-provides authentication and integrity checking services to any cryptographic system where it’s used. (Under the hood it is the AES algorithm)