Cs 3600 Final Exam Section 11

Front 1

Circuit switched vice packet switched

Back 1

In a circuit switched network, a dedicated path is maintained between the source and destination for the duration of the session
In a packet switched network, message data is divided into separate packets that may travel different routes to the same destination
•The packets share the route with packets from other users

Front 2

. Traffic Flow Analysis

a. What is it and how is it addressed?

Back 2

Inference of information through the examination of message attributes rather than message contents

Front 3

End-to-End Encryption.

Back 3

User A instructs her e-mail application program to encrypt a message for recipient B
•When the packets leave the client system the data in the packets will be encrypted

Front 4

Link encryption.

Back 4

A special network is needed
–It has encryption/decryption devices at every connection to every intermediate node

Front 5

a. Gateway-to-Gateway VPN.

Back 5

The gateway-to-gateway VPN implementation replaces an expensive dedicated leased network by using encryption over the Internet
•Each branch office installs a VPN device at their Internet gateway

Front 6

b. Client-to-Gateway VPN.

Back 6

The client-to-gateway VPN implementation replaces the need for expensive 800 phone numbers for remote access
•A VPN device is installed at the corporate Internet gateway and VPN software is installed in selected client systems, often laptops
This traffic can be encrypted and encapsulated

Front 7

• Application-based end-to-end encryption take place at what layer?

Back 7

Layer 7 Application Applications

Front 8

• Link encryption takes place at what layer?

Back 8

Layer 2 Data link E.g., Ethernet

Front 9

• VPN IPSec encryption takes place at what layer?

Back 9

Layer 3 Network E.g., IP

Front 10

Passive attack

Back 10

The attacker can only see the packets

Front 11

Active attack

Back 11

The attacker has the ability to read, copy and modify network packets and to insert new packets

Front 12

Circuit Switched Network

Back 12

In a circuit switched network, a dedicated path is maintained between the source and destination for the duration of the session

Front 13

Packet Switched Network

Back 13

In a packet switched network, message data is divided into separate packets that may travel different routes to the same destination

Front 14

Packet

Back 14

Messages are chopped up into packets or datagrams•Packets have a header and data

Front 15

Packet Header

Back 15

Contains source and destination addresses.

Front 16

Encapsulation

Back 16

The encapsulation feature can make the remote client appear as if it is an internal system with all the privileges of an internal client

Front 17

Traffic Flow Analysis

Back 17

Inference of information through the examination of message attributes rather than message contents

Front 18

End-to-End Encryption

Back 18

Since the data is encrypted before it leaves the system A it is protected until it is inside system
•Traffic flow analysis is very vulnerable
Since encryption and decryption is taking place on user client systems, the end users are managing their keys
•The end user decides what to encrypt
–It is possible that they will occasionally make a mistake and forget to encrypt a sensitive message

Front 19

Link Encryption

Back 19

A special network is needed
–It has encryption/decryption devices at every connection to every intermediate node

Front 20

Virtual Private Network

Back 20

If traffic is encrypted and authenticated over a public network (e.g., the Internet) it simulates a private network