What is used to hide data from unauthorized users by allowing a relation in a database to contain multiple tuples with the same primary keys with each instance distinguished by a security level?
Correct Answer: B
Polyinstantiation enables a relation to contain multiple tuples with the same primary keys with each instance distinguished by a security level. Instead of just restricting access, another set of data is created to fool the lower-level subjects into thinking that the information actually means something else. Data mining is the process of extracting and processing the information held in a data warehouse into something useful. Cell suppression is a technique used to hide specific cells that contain information that could be used in inference attacks. Noise and perturbation is a technique of inserting bogus data to misdirect an attacker.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-
Hill/Osborne, 2002, chapter 11: Application and System Development (page 727).