tailieunhanh - Network Security Chapter goals

A layer communicates with the equivalent layer in a different node. In order to get data to a peer layer, though, the layer at the transmitting node gives the data to the layer below it (on the same node), which adds a header containing additional information if necessary, and that layer in turn gives it to the layer below. As the packet is received by the destination node, each layer reads and strips off its own header, so that the packet received by layer n looks to that layer just like it did when it was sent down to layer n−1 for transmission. This seven-layer model. | Chapter 8 Network Security Chapter goals understand principles of network security o cryptography and its many uses beyond confidentiality o authentication o message integrity o key distribution security in practice o firewalls o security in application transport network link layers 8 Network Security 8-1 Chapter 8 roadmap What is network security Principles of cryptography Authentication Integrity Key Distribution and certification Access control firewalls Attacks and counter measures Security in many layers 8 Network Security 8-2 What is network security Confidentiality only sender intended receiver should understand message contents o sender encrypts message o receiver decrypts message Authentication sender receiver want to confirm identity of each other Message Integrity sender receiver want to ensure message not altered in transit or afterwards without detection Access and Availability services must be accessible and available to users 8 Network Security .