3.3 Wireless Network Flashcards
What devices can use Wi-Fi?
Laptops, desktops, tablets, smartphones (IoT devices like lights, Tv’s etc.)
What devices can use bluetooth?
Wireless headphones, connecting phones to car entertainment systems, keyboards etc.
What is bluetooth?
A wireless method of connecting devices together over a short distance
Features of bluetooth
- Uses radio waves at 2.4GHz
- Devices are typically 10 metres of each other
What is Bluetooth pairing?
- A persistent link is made between the 2 devices
- A device can ask for a passkey in order to pair to it - gives a layer of security like a password
- When a paired device is close enough to communicate it will say that it is connected
What are passkeys?
Passkeys only need to be entered once and will be remembered by devices that are paired
Wireless transmission
Commonly uses radio waves for communication
Why is wireless transmission not reliable?
Susceptible to interference from objects and other nearby electronic or radio devices
Wireless NICs
Built into every networked device capable of connecting to a wireless network
Examples of devices that use NIC’s
- PCs
- Smart Phones
- Wireless speakers
WAP (Wireless access point)
A device that allows wireless devices to connect to a wired network using Wi-Fi
The AP usually connects to a router via a wired network
802.11 types
- 11b/g/n uses 2.4GHz frequency
802. 11a/n/ac uses 5GHz frequency
802.11b/g/n uses 2.4GHz frequency Advantages and Disadvantages
- Greater range and coverage
- More interference from other devices as this is a crowded frequency
802.11a/n/ac uses 5GHz frequency Advantages and Disadvantages
- Less crowded space with 23 non-overlapping channels with higher data transmission rates
- Less able to penetrate through walls
What is intercepting data
Any intercepted data can be read and understood unless the data is encrypted
What is encryption?
Encryption is the encoding of data so that it can no longer be easily understood by a shift cipher
Plaintext
Original message to be encrypted
Ciphertext
The encrypted message
Encryption
The process of converting plaintext into ciphertext
Key
A sequence of numbers use to encrypt or decrypt, often data using a mathematical formula
Encryption algorithm
The formula for encrypting the plaintext
What are the 2 inputs for encryption?
Plaintext and a secret key
Encryption techniques
Private key (Symmetric encryption) Public key (Asymmetric encryption)
What is private key?
A single key is used to encrypt and decrypt a message and must be given to the recipient of your message to decrypt the data
What is a public key?
2 keys are used - one (public key) to encrypt and the other (private key) to decrypt data
This is more secure as it means that you never have to send or reveal your decryption key
What is the Caesar Shift Cipher?
Earliest substitution cipher where each letter is replaced by a a letter n positions further on in the alphabet (symmetric encryption)q
What methods of encryption are used when using wireless networks?
Most common wireless security standards are WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access)
Why should you use WPA or WPA2 encryption methods?
The WEP method of encryption is older and can be cracked in seconds
Why is HTTPS recommended for websites?
It encrypts data sent to and received from the site
Strong encryption
When the useful lifetime of the encrypted data is less than the time taken to break the code
Weak encryption
Code may be broken in time to use the information, but a lot of effort is required it might not be worth it
How you could use wireless networks and network security in your life?
We use a wireless router at home. This contains a switch, route and modem all in one box. All our mobile devices connect to the WAP with Wi-Fi. It is encrypted with WPA2. We don’t use WEP as it is insecure. Where possible we try to connect to websites with HTTPS as this makes all data transmitted secure. Our TV and soundbar are connected to the box using Ethernet cables. Bluetooth is used to connect our headphones to smartphones
