1. Database Security Jagdish S. Gangolly School of Business
State University of New York at Albany
NOTE: These notes are based on the book Security in Computing, by Charles & Shari Pfleeger, and are prepared solely for the students in the course Acc 661 at SUNY Albany. They are not to be used by others without the permission of the instructor.
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

2. Acc 661 Auditing of Adv Acctg Info Systems
Database Security
Security requirements
Physical database integrity
Logical database integrity
Element integrity
Auditability
Access control
User authentication
Availability
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

3. Example of Oracle DBMS Architecture
Source:
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

4. Database Integrity & Auditability
Field Checks (Domain)
Access control
Maintenance of change log
Granularity problem
Pass-through problem
Direct access of data vs. Inference problem
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

5. Database reliability & Integrity
Two-phase update: intent phase and commit phase
Redundancy/internal consistency
Error correction codes
Shadow fields
Backup and recovery procedures
Concurrency/Consistency/Deadlock management
Monitors and range comparisons
State constraints (eg., commit flag) and Transition constraints (eg., referential integrity)
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

6. Acc 661 Auditing of Adv Acctg Info Systems
Inference Problem
Direct vs. Indirect attacks
Tracker attacks:
count((SEX=F)  (RACE=C)  (DORM=Holmes))
= count(SEX=F) – count((SEX=F) 
((RACE  C) (DORM  Holmes)))
Linear system vulnerability (inference by solving equations)
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

7. Controls against Inference Attacks
Controls applied against queries
Controls applied against individual items in the database
Suppression: sensitive data values are not provided (query is rejected)
Concealment: answer provided is close, but not the actual value
Limited response suppression: Low frequency elements are not displayed
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

8. Approaches to the Inference Problem
Suppress obviously sensitive information
Track what the user knows
Disguise data (random perturbation, rounding, …)
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems

9. Acc 661 Auditing of Adv Acctg Info Systems
12/6/2018
Acc 661 Auditing of Adv Acctg Info Systems