T3 - Wireless networking Flashcards
Bluetooth
- is a wireless method of connecting devices together over a short distance
bluetooth
uses radio waves at 2.4 GHz
Pairing -
A persistent link is made between the two devices
passkey
in order to pair to it
- gives a layer of security like a password
Passkeys only need to be entered ..
once and will be remembered by devices that are paired
Wireless transmission
- uses radio waves for communication
Susceptible to interference
Wireless NICs
- Built into every networked device capable of connecting to a wireless network
Wireless Access Point (WAP) -
device
that allows wireless devices to connect to
a wired network using Wi-Fi
AP
usually connects to a router via a wired network
Encryption:
encoding of data so that it can no longer be easily understood
Plaintext
: the original message to be encrypted
Ciphertext:
the encrypted message
Encryption: the process of
converting plaintext into ciphertext
Key:
a sequence of numbers used to encrypt or decrypt, often data using a mathematical formula
Encryption algorithm:
the formula for encrypting the plaintext
Encryption techniques:
-private key
-public key
Private key
(Symmetric encryption):
A single key is used to encrypt and decrypt a message
must be given to the recipient of your message to decrypt the data
Public key
(Asymmetric encryption):
Two keys are used - one (public key) to encrypt and the other (private key) to decrypt data
more secure = never have to send or reveal your decryption key
Caesar shift cipher:
earliest known substitution cipher
symmetric encryption
-most basic type + the most insecure
- Letters of the alphabet are shifted by a given number
Caesar shift cipher: process
Each letter is replaced by a letter n positions further on in the alphabet
n is the key and is used to encrypt and decrypt the message
Symmetric encryption:
Same key used to encrypt and decrypt a message
Public key (Asymmetric) encryption:
Two keys are used: a public key known to everyone for encrypting and a private key for decrypting
Interception in wifi/ethernet
Wi-Fi signal can be listened to from a distance
Ethernet and fibre optic cables can also be intercepted
Wireless encryption: eg
Examples = WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access)
The WEP method of encryption is older and less secure
HTTPS should be used for websites as it encrypts data sent to and received from the site
Strong encryption
= useful lifetime of the encrypted data is less than the time taken to break the code.
Weak encryption,
the code may be broken in time to use the information, but it wouldn’t be worth the effort trying
2.4GHz pros
Greater range and coverage
2.4GHz cons
More interference from other devices as this is a crowded frequency
5GHz pros
Less crowded space with 23 non-overlapping channels with higher data transmission rates
5GHz cons
Less able to penetrate through walls
