ISC Exam Questions

Data inference violations can be reduced using

Data inference violations can be reduced using

A.
Polyinstantiation technique.

B.
Rules based meditation.

C.
Multi-level data classification.

D.
Correct-state transformation.

Explanation:
“Polyinstantiation is the development of a detailed version of an object from another object using
different values in the new object. In the database information security, this term is concerned with
the same primary key for different relations at different classification levels being stored in the same
database. For example, in a relational database, the same of a military unit may be classified Secret
in the database and may have an identification number as the primary key. If another user at a lower
classification level attempts to create a confidential entry for another military unit using the same
identification number as a primary key, a rejection of this attempt would imply to the lower level
user that the same identification number existed at a higher level of classification. To avoid this
inference channel of information, the lower level user would be issued the same identification
number for their unit and the database management system would manage this situation where the
same primary key was used for different units.” Pg 352-353 Krutz: The CISSP Prep Guide: Gold
Edition.
“As with aggregation, the best defense against inference attacks is to maintain constant vigilance
over the permissions granted to individual users. Furthermore, intentional blurring of data may be
used to prevent the inference of sensitive information.” – Ed Tittle CISSP Study Guide (sybex)
The other security issue is inference, which is very similar to aggregation. The inference problem
happens when a subject deduces information that is restricted from data he has access to. This is
seen when data at a lower security level indirectly portrays data at a higher level…This problem is
usually dealt with in the development of the database by implementing content and
contextdependent classification rules; this tracks the subject’s query requests and restricts patterns
that
represent inference.
“Polyinstantiation is a process of interactively producing more detailed versions of objects by
populating variables with values or other variables”- Shon Harris All-in-one CISSP Certification Guide
pg 725-727