文档介绍：Chapter work Security
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working: A Top Down Approach Featuring the , 3rd edition. Jim Kurose, Keith Ross Addison-Wesley, July 2004.
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8: Network Security
Chapter 8: Network Security
Chapter goals:
understand principles work security:
cryptography and its many uses beyond “confidentiality”
authentication
message integrity
key distribution
security in practice:
firewalls
security in application, transport, network, link layers
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8: Network Security
Chapter 8 roadmap
What work security?
Principles of cryptography
Authentication
Integrity
Key Distribution and certification
Access control: firewalls
Attacks and counter measures
Security in many layers
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8: Network Security
What work 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
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8: Network Security
Friends and enemies: Alice, Bob, Trudy