Overview

1. Overview CSSE 490 Computer Security Mark Ardis, Rose-Hulman Institute March 8, 2004

2. Acknowledgements Many of these slides came from Matt Bishop, author of Computer Security: Art and Science

3. Web 1: Getting Started (1/3) • Due Friday, March 12 • Subscribe to rhit.csse.security • Publishing • Reply to the article entitled "My Home Town" • Include a website describing your home town.

4. Web 1: Getting Started (2/3) • Reviewing • Read some of the postings by your fellow students and follow the links to the websites. • Review at least 3 of those websites • Assign a score for each of the key attributes • Give your justification for those scores • Reply to the original posting about that site with your review

5. Web 1: Getting Started (3/3) • Review Scores (0-5 for each, where 0 is worst and 5 is best) • Accuracy • Completeness • Up-to-date • Ease of Use • Links

6. Overview of Course Website http://www.rose-hulman.edu/class/csse/csse490/csse490-security/index.html

7. Chapter 1: Introduction • Components of computer security • Threats • Policies and mechanisms • The role of trust • Assurance • Operational Issues • Human Issues

8. Basic Components • Confidentiality • Keeping data and resources hidden • Integrity • Data integrity (integrity) • Origin integrity (authentication) • Availability • Enabling access to data and resources

9. Classes of Threats • Disclosure - unauthorized access • Snooping • Deception - acceptance of false data • Modification, spoofing, repudiation of origin, denial of receipt • Disruption - interruption of correct operation • Modification • Usurpation - unauthorized control • Modification, spoofing, delay, denial of service

10. Policies and Mechanisms • Policy says what is, and is not, allowed • This defines “security” for the site/system/etc. • Mechanisms enforce policies • Composition of policies • If policies conflict, discrepancies may create security vulnerabilities

11. Goals of Security • Prevention • Prevent attackers from violating security policy • Detection • Detect attackers’ violation of security policy • Recovery • Stop attack, assess and repair damage • Continue to function correctly even if attack succeeds

12. Trust and Assumptions • Underlie all aspects of security • Policies • Unambiguously partition system states • Correctly capture security requirements • Mechanisms • Assumed to enforce policy • Support mechanisms work correctly

13. Types of Mechanisms secure broad precise set of reachable states set of secure states

14. Assurance • Specification • Requirements analysis • Statement of desired functionality • Design • How system will meet specification • Implementation • Programs/systems that carry out design

15. Operational Issues • Cost-Benefit Analysis • Is it cheaper to prevent or recover? • Risk Analysis • Should we protect something? • How much should we protect this thing? • Laws and Customs • Are desired security measures illegal? • Will people do them?

16. Human Issues • Organizational Problems • Power and responsibility • Financial benefits • People problems • Outsiders and insiders • Social engineering

17. Tying Together Threats Policy Specification Design Implementation Operation

18. Key Points • Policy defines security, and mechanisms enforce security • Confidentiality • Integrity • Availability • Trust and knowing assumptions • Importance of assurance • The human factor