Network Security Flashcards
What is the process of developing a digitial signature ?
A user will have a memo, this memo will be hashed with their private key, this will be the signature, this is sent to the other user, this will be decrypted with the public key, this is how they will found out, to check message integrity the memo will be hashed again and then the digest will be compared
What is a symmetric key encryption ?
Where the same key that is used to encrypt will decrypt the data
What is public key encryption ?
Where a user will have a public and a private key, they will share the public key, their data will be encrypted using their private key and will decrypt their data using the public key
What is monoalphabetic encryption ?
One letter is swapped for another
What is polyalphaebtic encryption ?
Where there are multiple monoalphabetic encryption methods used within data.
What is the AP1.0 ?
Where a user will say that they are who they say they are
What are the ways in which mono and polyalpahbetic encryption can be broken ?
Known cipher attack, Chosen cipher attack, Cipher text attack
What is known cipher text attack ?
An intruder will make someone say something that will enable them to obtain the cipher forms of all the letters in the alphabet
What is a cipher text attack ?
Statistical analysis as well as brute force will be used to break the encryption method
What is a NONCE ?
This is a once in a lifetime protocol number that is used when using end user auth
What are the principles of network security ?
End user authentication, data integrity and confidentiality
What are the 3 methods of SSL and what do they include ?
Data transfer, key derivation and SSL handshaking
What is the reason for VPNS ?
For hosts and servers to communicate securely
What are the two ways someone can establish a VPN ?
Creating a standalone network or creating a network on top of the public internet
What is IPSEC ?
A protocol suite used in the network layer to secure network layer datagrams
What kind of coverage is this said to have ?
Blanket converage
What are the two protocols used in IPSEC ?
AH (authentication header )and ESP (Encapuslated security payload )
What is the authentication header protocol ?
Provides source and destination authentication and data integrity
What is ESP better the AH ?
Because ESP provides confidentiality
What is a SA?
Security Association
What is the characteristic of a securirty association ?
Two way conncetion between a host and a server
What were the downfalls of 802.11 ?
Single authentication method, no use of keys, weak encryption methods
How does 802.11i make up for 802.11 ?
Uses authentication methods to identify hosts and severs.
How do the access points nodes and severs authenticate each other ?
They use public key techniques
What is a firewall ?
A device that monitors a network, that contains packet filtering systems, that will allow or disallow packets of data passing through. Protects on interal network from the outside internet
What is stateful packet filtering ?
Where a packet filter will montior the TCP connection and detect behaviours of the packets recieved
What is an application gateway and what does it do ?
Application gateways are gateways in which all application data must pass through, packets that pass through will be deeply inspected. As their protocols, their headers and application are inspected
What are the 3 goals of firewalls ?
Allow traffic to pass through, must be impenetrable, authroized traffic must pass through.
How can they make up for a digitial signature or a MAC
They can use the NONCE method
What is the nonce method ?
They will use a once in a lifetime protocol code, Bob to authenticate alice will do this.
Alice will message bob
Bob will send the nonce (once in a lifetime code) to alice
Alice will encrypt it using her private key and send it back to bob
Bob will decrypt and then see the same code again
This will overcome a playback attack
How do you authenticate a user ?
Digital signatures, Public key encryption
How do you check for data integrity ?
Using message authentication codes
What are the 3 forms of attacks ?
Brute force, Eavesdropping, replay attack, playback attack
