计算机网络：自顶向下 配套PPTChapter_8_V7.0.pptx

Chapter 8SecurityA note on the use of these Powerpoint slides:We’re making these slides freely available to all (faculty, students, readers). They’re in PowerPoint form so you see the animations; and can add, modify, and delete slides (including this one) and slide content to suit your needs. They obviously represent a lot of work on our part. In return for use, we only ask the following:Computer Networking: A Top Down Approach If you use these slides (e.g., in a class) that you mention their source (after all, we’d like people to use our book!)If you post any slides on a www site, that you note that they are adapted from (or perhaps identical to) our slides, and note our copyright of this material.Thanks and enjoy! JFK/KWR All material copyright 1996-2016 J.F Kurose and K.W. Ross, All Rights Reserved7th edition Jim Kurose, Keith RossPearson/Addison WesleyApril 2016Security8-Chapter 8: Network SecurityChapter goals: understand principles of network security: cryptography and its many uses beyond “confidentiality”authenticationmessage integritysecurity in practice:firewalls and intrusion detection systemssecurity in application, transport, network, link layersSecurity8-Chapter 8 roadmap8.1 What is network security?8.2 Principles of cryptography8.3 Message integrity, authentication8.4 Securing e-mail8.5 Securing TCP connections: SSL8.6 Network layer security: IPsec8.7 Securing wireless LANs8.8 Operational security: firewalls and IDSSecurity8-What is network security?confidentiality: only sender, intended receiver should “understand” message contentssender encrypts messagereceiver decrypts messageauthentication: sender, receiver want to confirm identity of each other message integrity: sender, receiver want to ensure message not altered (in transit, or afterwards) without detectionaccess and availability: services must be accessible and available to usersSecurity8-Friends and enemies: Alice, Bob, Trudywell-known in network security worldBob, Alice (lovers!) want to c