Encryption-Based Multilevel Model for DBMS - Multilevel Security for Relational Databases - page 111

Table 5.5 Comparative Study between Encryption-Based Multilevel Database and Other
Multilevel Database Security Models

ENCRYPTION-
BASED
MULTILEVEL
DATABASE

BELIEF-
CONSISTENT
MLS

MODEL/
CRITERIA

JAJODIA-
SANDHU

SMITH-
WINSLETT

SEAVIEW MLR

Performance
in minutes

47 35 3 6 25 2

Encryption Not

supported

Not
supported

Not
supported

Not
supported

Not
supported

Supported

Table 5.5 gives a comparative study between the proposed
encryption-based multilevel database model and the other multilevel
database security models.

5.6 Summary

The encryption-based multilevel database model is implemented by
adding an encryption system as an additional layer of security over
the MLR model in multilevel relational database security. A working
multilevel secure database prototype was implemented in a Microsoft
SQL server database to measure the performance experiments that
were instrumented using the system. Also, this chapter measured the
impact of supporting encryption in the multilevel relational database;
the overhead of the encryption of data insertion and decryption of
data retrieval are included in the performance study.
Supporting encryption in multilevel relational databases improves
the performance of the retrieving of data in the SELECT and JOIN
queries. This improvement in the performance due to the relational
database size is decreased because the extra attributes used for the
class levels are replaced by supporting the encryption in the multilevel
relational database. Also, the multilevel relational database design is
easier because there is no change in the structure of the base table.
Supporting encryption in the multilevel relational database has a bad
performance because of the extra CPU processing results from sup-
porting the encryption algorithm in an MLS database. When sup-
porting the encryption algorithm in the UPDATE query is executed,
we decrypt the data, ensure the condition of the update statement,
execute the update statement, and encrypt the data again.