Computer Networking Chapter 8 A Top-Down Approach Security KUROSE ROSS A note on the use of these ppt slides: Computer 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. Networking:A 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 Top Down ask the following: If you use these slides (e.g.,in a class)that you mention their source Approach (after all,we'd like people to use our book!) 6th edition 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 Jim Kurose,Keith Ross material. Addison-Wesley Thanks and enjoy!JFK/KWR March 2012 urhts Reserved 8-1
8-1 Chapter 8 Security Computer Networking: A Top Down Approach 6th edition Jim Kurose, Keith Ross Addison-Wesley March 2012 A note on the use of these ppt 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: 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 1996-2012 J.F Kurose and K.W. Ross, All Rights Reserved
Chapter 8:Network Security Chapter goals: understand principles of network security: cryptography and its many uses beyond “confidentiality" authentication ·message integrity security in practice: firewalls and intrusion detection systems security in application,transport,network,link layers Network Security 8-2
Network Security 8-2 Chapter 8: Network Security Chapter goals: understand principles of network security: cryptography and its many uses beyond “confidentiality” authentication message integrity security in practice: firewalls and intrusion detection systems security in application, transport, network, link layers
Chapter 8 roadmap 8.1 What is network security? 8.2 Principles of cryptography 8.3 Message integrity,authentication 8.4 Securing e-mail 8.5 Securing TCP connections:SSL 8.6 Network layer security:IPsec 8.7 Securing wireless LANs 8.8 Operational security:firewalls and IDS Network Security 8-3
Network Security 8-3 Chapter 8 roadmap 8.1 What is network security? 8.2 Principles of cryptography 8.3 Message integrity, authentication 8.4 Securing e-mail 8.5 Securing TCP connections: SSL 8.6 Network layer security: IPsec 8.7 Securing wireless LANs 8.8 Operational security: firewalls and IDS
What is network security? confidentiality:only sender,intended receiver should “understand”message contents sender encrypts message 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 Network Security 8-4
Network Security 8-4 What is network security? confidentiality: only sender, intended receiver should “understand” message contents sender encrypts message 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
Friends and enemies:Alice,Bob, Trudy well-known in network security world Bob,Alice (lovers!)want to communicate "securely" Trudy (intruder)may intercept,delete,add messages Alice Bob channel data,control messages data secure secure data sender receiver Trudy Network Security 8-5
Network Security 8-5 Friends and enemies: Alice, Bob, Trudy well-known in network security world Bob, Alice (lovers!) want to communicate “securely” Trudy (intruder) may intercept, delete, add messages secure sender s secure receiver channel data, control messages data data Alice Bob Trudy