QMCS 490 - Class Today

1. QMCS 490 - Class Today • Information Security life cycle • Introductions • Security perimeters • Assignment R. Smith - University of St Thomas - Minnesota

2. The life cycle • Identify your practical goals • What “real” things do you want to accomplish? • What threats interfere with them? • Implement security measures • What weaknesses exist? • What security measures might work? • What are the trade-offs against goals? • Measure success • Monitor for attacks or other failures • Recover from problems • Reassess goals and trade-offs R. Smith - University of St Thomas - Minnesota

3. So what will the class look at? • How to assess security in general • Analyzing risk trade-offs • Specific security issues and techniques • Workstations • LANs • Distributed networks • Internet access • E-commerce • If time, DRM and ‘extreme security’ R. Smith - University of St Thomas - Minnesota

4. Who are you, who am I • Ask your neighbor: • Name, major • Why are you taking this class? • Do you “0wn” a computer? • I.e. can you log in as admin? • Give a personal, security related fact. • Experience, skill, incident, etc. R. Smith - University of St Thomas - Minnesota

5. Why this course exists • Start of an Information Security major • Will be US govt certified • Four principal ‘special’ courses • Intro course = this one • Operating Systems • Networking • Infosec Analysis = capstone course • Analysis course • More labs and tools • More (very dry) government policy stuff • Info Warfare exercise at the end R. Smith - University of St Thomas - Minnesota

6. The Syllabus: nuts and bolts • Grade = assignments + tests • Also a ‘participation’ grade • Attend class, hand in work = good test grade • Good grade <= assignments, attend class • Typical homework • Analyze a security problem, draw a diagram • I am planning a couple of labs • We have limited lab space (5 machines) • May do 30 minute shots at the labs • I typically have people do research projects • An outline, a paper, and a presentation. • Not sure this time R. Smith - University of St Thomas - Minnesota

7. The Syllabus • Concepts we’ll cover • “Practical” security planning and assessment • Risk trade offs - the concept • Role of security policies • Environments - in order of breadth • Personal desktop/laptop • Shared computer • Local network • Internet access from LAN • Distributed LANs • E-commerce R. Smith - University of St Thomas - Minnesota

8. Two security assessment techniques • Perimeter analysis • Look at the boundary protecting an asset • Look at access points in the boundary • Who might want the asset? • What attacks will break the boundary? • What attacks will break the access points? • Is the inside benign itself? Can it be hacked? • Flow analysis (data flow, execution flow) • Look at where data might flow • Assess mechanisms to restrict the flow • Assess attacks that can divert the flow • Look at “flow of execution” and possible diversion R. Smith - University of St Thomas - Minnesota

9. Part of this semester’s agenda • I’m writing a book on elementary security • We’ll look at chapters in this class • I thought I’d have one ready for today • It’s not finished yet. • Internet Cryptography • An “old” book, but … • It talks about security, perimeters, and information flow • Provides the basics and concepts for networking & crypto R. Smith - University of St Thomas - Minnesota

10. Personal Computer Security • Share a dorm room? • Share an apartment? • Share a home? • “My” computer - a security objective • “I’ll kill you if you touch it” • a policy statement? R. Smith - University of St Thomas - Minnesota

11. Extreme Workstation Security Does this achieve our goals? R. Smith - University of St Thomas - Minnesota

12. Threat Vulnerability Defense,Safeguard, or “Countermeasure” Asset Threats & Vulnerabilities An attempt to steal or harm the asset is an attack R. Smith - University of St Thomas - Minnesota

13. A real world example • There is a company • Thieves walk into their buildings every day • The front door is unlocked all day long • Valuable company property is just lying around • The thieves pick it up and carry it away • Most thieves, but not all, get away? • WHAT IS THIS STUPID COMPANY? • Why don’t they lock the door, at least? R. Smith - University of St Thomas - Minnesota

14. Security analysis: your PC • Threats? • Who, why? • Vulnerabilities? • What bad can happen? • What allows the badness to happen? • Can we just lock it up? • Put it in a room • Put a lock on the door. • Don’t share the key • Does this work? R. Smith - University of St Thomas - Minnesota

15. Physically securing an area • What is a secure perimeter? • Contiguous - no breaks • A barrier - actually blocks some attacks • Minimal number of openings • Access restrictions on the openings • Example: my house • Wooden frame building - keeps out wild dogs • Glass windows with storms - ditto • Locked doors - ditto • Metal fence - ditto • Gates in the fence - ditto R. Smith - University of St Thomas - Minnesota

16. Security Analysis • What are the threats? • Wild dogs • Burglars • People collecting for nasty charities • What are the defenses? • Are there effective attacks on them? • Effective = threats might use them R. Smith - University of St Thomas - Minnesota

17. Is this a complete list of threats? • Of course not. • Study history, the news, experience, introspection • Generate a ‘better’ list • A notion of “threats” • Threat = anyone with strongly different goals • Example: Burger King vs McDonald’s • Both “sort of” have the same goal: sell burgers • In fact, BK wants to sell BK burgers, while Mac wants to sell Mac burgers • BK people are not trusted in McDonald’s places R. Smith - University of St Thomas - Minnesota

18. Potential vs Real Threats • Potential Threat = strongly different goals • Not a member of the family, company, community • Member of competing entity • But not necessarily motivated to do you harm • Real Threat = history of attacks • “Good” neighborhood = neighbors not a threat • “Bad” neighborhood = neighbors have caused trouble in the past R. Smith - University of St Thomas - Minnesota

19. Now, the Defenses • Physical world • Physical barriers, slows them down a lot • Locks - slow them down, restricts access • Alarms - calls for help • Warnings - shows you care • Computer world • Examples? R. Smith - University of St Thomas - Minnesota

20. What defenses are “effective”? • Concept of “work factor” • How hard does the attacker have to work to overcome the defense? • May be computed in hours • May be computed in likelihood over time • Example: average of 3 days, $.25M to crack DES • Effective = • Work Factor > threat’s motivation or skill • My Home Example • Wild dogs motivated but not resourceful • Charity people resourceful but not motivated • Burglars may be both, but hopefully not too much so • Or, deterred by the alarm, and the large dog R. Smith - University of St Thomas - Minnesota

21. How does this relate to computers? • Defenses are always a trade off • The same reasoning applies to both • All security begins with physical security R. Smith - University of St Thomas - Minnesota

22. Evolution of Attacks and Defenses Attacks Defenses ?? One-Time Passwords Network Sniffing Password Tokens Password Sharing Memory Protection Keystroke Sniffing Guess Detection Guessing Password Hashing Steal the Password File Passwords Masquerade Remote Terminals Example: Passwords on Computers R. Smith - University of St Thomas - Minnesota

23. The homework assignment • Two parts • A: describe your computer sharing “policy” • B: describe physical protection of your computer R. Smith - University of St Thomas - Minnesota

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