Internet Security Flashcards
(14 cards)
What is a firewall?
Hardware and or software for protecting against unauthorised access to a network acting as a barrier
What are two types of firewalls?
Hardware (physical devices)
Software(programs running on computers)
How does a firewall use packet filtering to protect a network?
Examines header information of each data packet coming in or out of a network and deciding whether to allow it or clock the packet based on predefined rules.
How does a firewall use Stateful Inspection to protect a network?
It monitors active network connections to identify and block threats
How does a firewall use ports to protect a network?
It controls whether or not a program can access or be accessed by your computer
How does a firewall use IP addresses to protect a network?
It identifies the source and destination of network traffic allowing it to filter incoming and outgoing data based on predefined rules
What is a proxy server?
A computer or device which allows connection between a user and internet e.g when you request a website the proxy server makes the request on your behalf and send the information back to you
How does a proxy server protect a network or device?
-Hides IP address
-Content filtering
-Caching
-Blocks dangerous Websites
-Tracks internet Usage
What is encryption?
Uses an algorithm to convert a message into a form that is not understandable without the key to decrypt it
What is symmetric encryption?
The same key is used to encrypt and decrypt a message, less security and hard to send key without interception
What is asymmetric encryption?
The sender uses the public key to encrypt it and receiver uses their private key to decrypt it, slower than symmetric encryption
What is a digital certificate?
An electronic document that proves the identity of a person, website or organisation.
What are key components of a digital certificate?
Public key-Used for encrypting and verifying digital signatures
Owner Information
Issuer information-the CA that issued certificate
Expiration date-validity period of certificate
Digital signatures Owner-a cyptographic signature from CA verifying identity
How do you produce a digital signatures?
-Message is hashed into a message digest(a hash) which is encrypted with senders private key
-Digest calculated from message which is a shortened value calculated from the message
This is transmitted with the message
Receiver would check certificate authority’s public key before decrypted using public key
Hashing function applied to text of message
The result is compared with digital signatures Owner Information
If same it is the digital signature
