Network Security Flashcards
(10 cards)
What are the 5 objectives of network security?
Confidentiality
Integrity
Availability
Authenticity
Accountability
What is mutual authentication?
When 2 communicating parties both confirm their identity to the other
A protocol has forward secrecy if it keeps the message secret from an attacker who has what?
A recording of the protocol run
The long term keys of the principals
What are the 2 requirements for a good key?
Freshness - the key is new
Exclusivity - the key is only known to the principals in the protocol
What are the 2 requirements for entity authentication?
Far-end operative - A knows that B is currently active
Once authentication - A knows that B wishes to communicate with A
What are the 3 requirements for a protocol to provide mutual belief in a key?
The key is a good key
A knows that B wishes to communicate with A using the key
A knows that B believes that the key is a good key for B
What is EAP?
Extensible Authentication Protocol
It is a framework for network access and authentication control. A client has to authenticate themselves to a authentication server before they get access to the rest of the network. It is extensible because it supports many authentication methods.
In IEEE 802.1X what is the difference between an uncontrolled port and a controlled port?
An uncontrolled port allows the exchange of data regardless of the authentication state of the client (so new clients can authenticate themselves). A controlled port only allows the exchange of data if the client is authenticated.
Why is the Wired Equivalent Privacy protocol insecure?
Same key for every user.
Uses RC4 stream cipher with a 24 bit IV. The same seed must not be used twice but 50% chance of IV reuse after 5,000 packets.
Why is WPA/WPA2 insecure?
Anyone with the network password can decrypt the encrypted packets.
