Network Security

Question 1

What is the process of developing a digitial signature ?

Answer 1

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

Question 2

What is a symmetric key encryption ?

Answer 2

Where the same key that is used to encrypt will decrypt the data

Question 3

What is public key encryption ?

Answer 3

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

Question 4

What is monoalphabetic encryption ?

Answer 4

One letter is swapped for another

Question 5

What is polyalphaebtic encryption ?

Answer 5

Where there are multiple monoalphabetic encryption methods used within data.

Question 6

What is the AP1.0 ?

Answer 6

Where a user will say that they are who they say they are

Question 7

What are the ways in which mono and polyalpahbetic encryption can be broken ?

Answer 7

Known cipher attack, Chosen cipher attack, Cipher text attack

Question 8

What is known cipher text attack ?

Answer 8

An intruder will make someone say something that will enable them to obtain the cipher forms of all the letters in the alphabet

Question 9

What is a cipher text attack ?

Answer 9

Statistical analysis as well as brute force will be used to break the encryption method

Question 10

What is a NONCE ?

Answer 10

This is a once in a lifetime protocol number that is used when using end user auth

Question 11

What are the principles of network security ?

Answer 11

End user authentication, data integrity and confidentiality

Question 12

What are the 3 methods of SSL and what do they include ?

Answer 12

Data transfer, key derivation and SSL handshaking

Question 13

What is the reason for VPNS ?

Answer 13

For hosts and servers to communicate securely

Question 14

What are the two ways someone can establish a VPN ?

Answer 14

Creating a standalone network or creating a network on top of the public internet

Question 15

What is IPSEC ?

Answer 15

A protocol suite used in the network layer to secure network layer datagrams

Question 16

What kind of coverage is this said to have ?

Answer 16

Blanket converage

Question 17

What are the two protocols used in IPSEC ?

Answer 17

AH (authentication header )and ESP (Encapuslated security payload )

Question 18

What is the authentication header protocol ?

Answer 18

Provides source and destination authentication and data integrity

Question 19

What is ESP better the AH ?

Answer 19

Because ESP provides confidentiality

Question 20

What is a SA?

Answer 20

Security Association

Question 21

What is the characteristic of a securirty association ?

Answer 21

Two way conncetion between a host and a server

Question 22

What were the downfalls of 802.11 ?

Answer 22

Single authentication method, no use of keys, weak encryption methods

Question 23

How does 802.11i make up for 802.11 ?

Answer 23

Uses authentication methods to identify hosts and severs.

Question 24

How do the access points nodes and severs authenticate each other ?

Answer 24

They use public key techniques

Question 25

What is a firewall ?

Answer 25

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

Question 26

What is stateful packet filtering ?

Answer 26

Where a packet filter will montior the TCP connection and detect behaviours of the packets recieved

Question 27

What is an application gateway and what does it do ?

Answer 27

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

Question 28

What are the 3 goals of firewalls ?

Answer 28

Allow traffic to pass through, must be impenetrable, authroized traffic must pass through.

Question 29

How can they make up for a digitial signature or a MAC

Answer 29

They can use the NONCE method

Question 30

What is the nonce method ?

Answer 30

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

Question 31

How do you authenticate a user ?

Answer 31

Digital signatures, Public key encryption

Question 32

How do you check for data integrity ?

Answer 32

Using message authentication codes

Question 33

What are the 3 forms of attacks ?

Answer 33

Brute force, Eavesdropping, replay attack, playback attack