CS%20285%20Network%20Security

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CS 285 Network Security

• Fall 2008

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Course Information

• When and Where
• Tuesday/Thursday 11am-1215pm
• 209 Featheringill Hall
• Instructor Yuan Xue (yuan.xue_at_vanderbilt.edu)
• Office 383 Jacobs Hall, Phone [phone]
• Office hours Monday/Thursday 2pm-3pm or by
  appointment.
• Web http//vanets.vuse.vanderbilt.edu/xue/cs285f
  all08/index.html

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Books and References

• Textbook
• WS Cryptography and Network Security
  Principles and Practice (4th Edition) by William
  Stallings
• Reference books
• KPS Network Security Private Communication in
  a Public World (2nd Edition), by Charlie Kaufman,
  Radia Perlman, Mike Speciner
• CSP Security in Computing (3rd Edition), by
  Charles P. Pfleeger, Shari Lawrence Pfleeger
• MB Computer Security Art and Science, by
  Matthew A. Bishop

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Course Component

• Lecture
• Slides white board
• Take note
• Online digest/slides
• Participation
• Discussion
• Presentation
• Homework
• 5 assignments
• Midterm
• Project

• Grading Policy
• Participation 10
• Homework 35
• Midterm 25
• Project 30

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What you will learn from this course

• What is Security?
• Where the security problems come from?
• Potential threats to a system
• What are the solutions?
• Apply an appropriate mix of security measures
  (protective, defensive, etc)
• Knowing what has worked, what has failed.

• Security involves many aspects
• Operating system, programming language,
  administration and policy
• Our Focus
• Network Security

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Course Topics

• Security Basics and Principles
• Symmetric/ Asymmetric Cryptography
• Basic concept, algorithm, mechanism,
• Design principles
• Security Practices
• Secure protocols, systems and applications
• Hand-on experiences
• Secure network programming
• Hot Topics and Recent Development
• Wireless security, DoS attack, etc.

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Survey and Feedback

• Your input is important
• Online Survey
• http//www.zoomerang.com/Survey/?pWEB22873V62YWQ
• Feedback

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What is security?

• In general, security is the condition of being
  protected against danger or loss. (Wikipedia)
• In computer security and network security
• What are the subjects that need to be protected?
• Lets start with some terms
• System
• computer, network, application, data, resource
• Principal an entity that participate in a system
• user, person

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What is security?

• Computer Security
• Confidentiality means that only authorized people
  or system can access the data or resource.
• Integrity refers to the trustworthiness of data
  or resources.
• Data integrity means that data can only be
  modified by authorized people or system in
  authorized ways
• Origin integrity means that the source of the
  data is trustworthy, also called authentication.
• Message authentication means messages received
  are exactly as sent (i.e. no modification,
  insertion, deletion, or replay), and the ID of
  the sender is valid.
• Note timing information
• Availability means that people has the ability to
  use the information or resource desired.

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Where the security problem comes from?

• Lets look at some example systems
• Bank
• Bookkeeping
• Core operations
• customer account, journals recording the
  transactions
• Who has the access to the information?
• Banks own staff what if they cheat?
• ATM
• Authenticate users based on card and ID number
• Lets go Internet
• The user how do we know they are the real
  (authenticate) user?
• Protect web servers and bookkeeping database

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Where the security problem comes from?

• Hospital
• Patient record system
• Who can access the record?
• Many parties insurance company, care giver,
  researcher, etc
• Complicated -- role can change
• Privacy issue HIPPA
• Anonymize the record for research
• Is it sufficient?
• Show me all records of 59-year-old males who were
  treated for a broken collarbone on September 15,
  1966
• Drug management
• Lets go to Web
• .

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Issues that will be addressed in this class
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Network Security Issues
Network Security

• From a Computer to Internet
• Single computer
• Networking environment
• Secure communication in a public environment
• Computer system security with remote access

Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
Read content of the message from Bob to Alice
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
Modify content of the message from Bob to Alice
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
capture the message from Bob to Alice And replay
the message later
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
Pretend to be Bob to send a message to Alice
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
Interrupt
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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Some Simple Scenarios
Alice
Bob
Observe message pattern
Darth
Application
Application
TCP/UDP
TCP/UDP
IP
IP
IP
IP
Link
Link
Link
Link
Internet
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What are the solutions?
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Why many solutions fail?

• Protect wrong things
• Protect right things in the wrong way

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What are the solutions?

• Security Basics and Principles
• Symmetric/ Asymmetric Cryptography
• Basic concept, algorithm, mechanism,
• Security Practices
• Secure protocol designs
• Secure systems and applications

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How to study network security?

• Principle of Easiest Penetration
• An intruder are expected to use any available
  means of penetration.
• Computer security specialists must consider all
  possible means of penetration.
• Learning methodology
• examine all possible vulnerabilities of the
  system
• consider available countermeasures.