Encryption-Based Multilevel Model for DBMS - Multilevel Security for Relational Databases - page 100

5.4 Performance Study

This section describes the performance study of multilevel relational
database security models such as SeaView, Jajodia-Sandhu, Smith-
Winslett, MLR, and belief-consistent models and the encryption-based
multilevel database and illustrates the impact of changing the size and
schema of the relational database on the performance of these models.
The machine that is used for the implementation consists of CPU
speed of 2.2 GHz, physical RAM size of 3 GB, and hard disk size of
320 GB. The software used in the implementation is a Microsoft SQL
server 2008 R2 and the experiments' measurements were captured at the
machine using a monitoring tool provided by the Microsoft SQL server.
Also, a prototype is implemented to determine the impact of the
encryption algorithms on a multilevel database and to find the suitable
algorithm to be used in the new encryption system. From Figure 5.6, we
observe that the suitable encryption algorithm is the AES_128 algorithm
that supports encryption with good performance and is cost effective.

5.4.1 Experimental Database Structure

The timesheet database consists of four relations and was created and
populated to facilitate our performance study. Timesheet system rela-
tions used in the implementation are described as follows:

• The employee relation provides information about employees:
• Employee(EMPID, Code, Name, Department, Type,
Contract, Shift, Religion, Job, Position, Address, City).
• The departure relation is used to store the departure notice of
each employee when he leaves the site of the work:
• Departure(EMPID, DepartureDate, ReturnDate,

D e p a r t u r eTy p e)
• The timesheet relation is used to store the timesheet of each
employee every day:
• TimeSheet(EMPID, Date, TimeSheet, OverTime,
Remarks)
• The annual rights relation is used to store the rights of each
employee every year:
• AnnualRights(EMPID, Year, Description, Inc, ADays,
GDays)