Managing Multi-User Databases (3)

1. Managing Multi-User Databases (3) IS 240 – Database Management Lecture #20 2004-04-27 Prof. M. E. Kabay, PhD, CISSP Norwich University mkabay@norwich.edu

2. Topics • Fundamentals of Information Security • Database Security • Database Recovery • Management Issues

3. Fundamentals of IA • The Classic Triad • Confidentiality • Integrity • Availability • The Parkerian Hexad • Possession • Authenticity • Utility • Information Assurance (IA)

4. The Classic Triad C I A

5. Confidentiality Restricting access to data • Protecting against unauthorized disclosure of existence of data • E.g., allowing industrial spy to deduce nature of clientele by looking at directory names • Protecting against unauthorized disclosure of details of data • E.g., allowing 13-yr old girl to examine HIV+ records in Florida clinic C

6. Integrity Internal consistency, validity, fitness for use • Avoiding physical corruption • E.g., database pointers trashed or data garbled • Avoiding logical corruption • E.g., inconsistencies between order header total sale & sum of costs of details C I

7. Availability Timely access to data • Avoid delays • E.g., prevent system crashes & arrange for recovery plans • Avoid inconvenience • E.g., prevent mislabeling of files A C I

8. Problem: Missing Elements • Which principle of the C-I-A triad has been breached when • A child takes bank card with password in envelope but does not open it? • Someone sends threat to President using your e-mail address but not your e-mail logon? • Someone converts all the salary figures in your database to Iraqi Dinars? ANSWER: NONE OF THEM – THE TRIAD IS INSUFFICIENT TO DESCRIBE SECURITY BREACHES

9. The Parkerian Hexad Protect the 6 atomic elements of INFOSEC: • Confidentiality • Possession or control • Integrity • Authenticity • Availability • Utility

10. Why “Parkerian?” Donn G. Parker Recipient of Lifetime Achievement Award from NCSC in 1993

11. Possession Control over information • Preventing physical contact with data • E.g., case of thief who recorded ATM PINs by radio (but never looked at them) • Preventing copying or unauthorized use of intellectual property • E.g., violations by software pirates A C P I

12. Authenticity Correspondence to intended meaning • Avoiding nonsense • E.g., part number field actually contains cost • Avoiding fraud • E.g., sender's name on e-mail is changed to someone else's Au Av C P A

13. Utility Usefulness for specific purposes • Avoid conversion to less useful form • E.g., replacing dollar amounts by foreign currency equivalent • Prevent impenetrable coding • E.g., employee encrypts source code and "forgets" decryption key U Au Av C P I

14. Functions of IA (1) • Avoidance: e.g., prevent vulnerabilities and exposures • Deterrence: make attack less likely • Detection: quickly spot attack • Prevention: prevent exploit • Mitigation: reduce damage • Transference: shift control for resolution

15. Functions of IA (2) • Investigation: characterize incident • Sanctions & rewards: punish guilty, encourage effective responders • Recovery: immediate response, repair • Correction: never again • Education: advance knowledge and teach others

16. Information Assurance (IA) Avoid Deter Educate Detect Correct Prevent Recover Mitigate Punish/reward Transfer Investigate

17. Database Security • Processing Rights • I&A • Individuals & User Groups • Application Security

18. MORE POWER / DANGER LESS POWER / DANGER Processing Rights • Who gets to do what to which records? • Different functions • Modify DB structure • Grant rights to users • Change records • Delete • Modify (change) • Insert • See entire records • See selected fields

19. I&A: Identification & Authentication • Each individual user has unique identifier • User ID for operating system logon • User ID for DBMS access • Connection between user ID and actual person is known as authentication based on • What you know • What you have • What you are • What you do • User IDs should never be shared

20. Individuals & User Groups • Individual users may have specific rights • Call this authorization or privileges for specific functions • Can also define rights for groups of people (aka role-based security) • Call these user groups; e.g., • Human resources clerks vs HR managers • Accounting book-keepers vs Accounting managers • Managers for different departments • May define “public” or “visitor” group if necessary • Provide safe privileges for specific functions • E.g., lookups, interactions for requesting info, subscribing to newsletter….

21. Application Security • DBMS security may not suffice for specific applications • Business rules may be more complex than simply assigning privileges according to identity; e.g., • Some patient records may be accessible to nurse or doctor only while they are treating a specific patient • Some financial information may be locked while SEC is performing an audit • Such requirements are programmed at the application level

22. Topics • Database Security • Database Recovery • Management Issues

23. Database Recovery • Transactions • Application Logging • Transactions and Log Files • Backups & Log Files • Recovery from Backups • Recovery from Log Files

24. Transactions • What are transactions? • Why would we care if a transaction were interrupted by a DBMS failure or a system failure?

25. Application Logging • Benefits of logging • Audit trail for security / investigations • Performance data • Debugging • What might a logging process write into the log file when a process is • Adding a record? • Changing a record? • Deleting a record?

26. Transactions and Log Files • Why would it matter to anyone that a log file keep a distinction among different transactions? • How does a log file mark an atomic transaction?

27. Backups & Log Files Distinguish among the following types of backups: • System vs application • Full (everything) • Differential (aka Partial) (everything changed since last full) • Incremental (everything changed since last incremental) • Delta (only changed data) • Log files (only the information about the changes)

28. Backup Types

29. Recovery from Backups • Discuss how one would use each of the following types of backup in recovering from a system failure • Full • Differential • Incremental • Delta

30. Recovery from Log Files • Roll-backward recovery • Use log file to identify interrupted (incomplete) transactions using checkpoints • How? ____________________________ • Remove all changes that are part of those incomplete transactions • Roll-forward recovery • Start with valid backup • Use log file to re-apply all completed transactions • Leave out the incomplete transactions • Which kind is faster?_____________________

31. Topics • Database Security • Database Recovery • Management Issues

32. Management Issues • Performance • Inflection points • Capacity • Application Evolution

33. Performance Management • Log files help DBAs monitor and improve application and system performance • Identify application errors quickly • Identify operators with high error rates • Calculate response times on different servers • Can monitor trends in • transaction volumes • Response times • Look for inflection points and study reasons

34. Inflection Points • Watch for changes in slope • Always find out why pattern has changed ? Resource Time

35. Capacity • Same reasoning: look for trends in disk space usage • Identify which applications are growing fastest • Project when you will need to increase storage capacity • Never let a database fill up to maximum capacity • Be curious about any sudden change in rate of growth – find out if there are problems

36. Application Evolution • All applications must change • Environment changes • Operating systems / DBMS versions • Regulations & laws • Business needs • Therefore databases change • DBAs must plan to meet demands for change • Keep track of structure, usage • Define data repository • Full metadata about all organization data systems

37. Homework • Finish very carefully reading all of Chapter 11 using the full SQ3R techniques. • REQUIRED by MONDAY NOON 3rd May (hand in at B&M office) for 26 points • Group I Questions #11.37 through 11.49 • ALL remaining outstanding homework is due by that date. No further extensions. • MK will return all homework to B&M office by Tuesday NOON • OPTIONAL also by Monday 3rd May for 3 extra points each • 11.52 and/or 11.53 on p. 327

38. Final Exam • Thursday 6 May 2004 • 08:00-10:30 • Dewey 211 • Covers entire course material • T/F, short answer, diagrams, short essay,

39. DISCUSSION