IMPLEMENTING CRYPTOGRAPHY IN DATABASE

KWAN SHONG HANN

A thesis submitted in fufflilment of the requirements for the award of the degree of

Bachelor of Computer Science (Computer Systems & Networking)

Faculty of Computer Systems & Software Engineering lJniversiti Malaysia Pahang

APRIL 2010

ABSTRACT

With the increasing dependency of database for data storage, many sensitive data

such as personal information data and credit card information data are being stored

inside a database. These data is so valuable that it attracts unauthorized personnel to gain

access for obtaining the data for further usage. Even though the network infrastructure

nowadays is protected with different kind of security measures, there is none of them is

able to block all the threats perfectly. Therefore, the data needs to be able to protect its

confidentiality even though all measures have been failed. This is where the importance

of cryptography in protecting the data confidentiality even the data is in the hands of the

attacker. Cryptography can be implemented in different kind of methods to secure the

database. The purpose of this study is to develop a cryptosystem that is able to

implement cryptography to the data before storing them into the database. This

implementation has been strengthened by introducing two approaches which are the

classification of types of data using Key Family and the classification of data encryption

key status according to the activation time. Key Family separates types of data such as

personal information data and credit card information data. Both families use different

data encryption key to encrypt and decrypt to limit the access of the attacker if one of the

key is obtained. The state of data encryption key is determined by the activation date

which the key which has the latest time will be activated and the old ones will be expired.

This will prevent the key remains too long for encryption and decryption which poses

risks for threats to break the key. This system is developed using Java programming

language with the use of Java Cryptography Extension for the cryptography process.

MySQL database is used as the protected database where all the data in the database is

encrypted for protection. Finally, it is hope that this system can provide better security

for data confidentiality and also become the last line defense of data towards the attacks.

V

ABSTRAK

Pengkalan data pada hari mi semakin diperlukan untuk menjadi tempat

penyimpanan data utama kepada perisian computer yang dibangunkan. mi menyebabkan

lebih banyak data yang sensitif seperti data peribadi individual dan data credit card. Data

tersebut adalah amat berharga sehingga ia mendorongkan pencerobohan terhadap

pengkalan data. Walaupun sistem rangkaian pada hari mi telah dilengkapi dengan

pelbagai jenis cara untuk mencegah pencerobohan terhadap rangkaian, tiada satu cara

yang dapat mencegahnya dengan sempuma. Oleh itu, data hendaklah diubahsuai supaya

ia dapat mempertahankan inlormasi yang terkandung dalamnya. mi dapat dicapai

dengan menggunakan teknik Cryptography terhadap data. Tujuan penyelidikan mi

adalah untuk membangunkan satu sistem akan mengapplikasikan cryptography terhadap

data sebelum ia disimpan dalam pengkalan data. Applikasi mi telah diperkuatkan dengan

penggunakan Key Family yang akan mengumpulkan jenis data yang sama menjadikan

keluarga yang sama. mi adalah untuk mengelakkan penceroboh dapat mendapatkan

semua data dengan hanya mendapatkan satu kunci tersebut. Kunci yang digunakan

untuk encrypt akan diperkenalkan dengan menggunakan masa activasi untuk mengubah

pengguna.an kunci dari semasa ke semasa. Kunci yang lama akan diganti dengan kunci

yang mempunyai masa yang terbaru. mi adalah untuk mengurangkan masa kunci yang

digunakan kerana masa adalah satu element yang penting bagi penceroboh untuk

mencapai kunci tersebut. Sistem mi dibangunkan dengan menggunakan bahasa

pengaturcara Java dengan applikasi Java Cnyptographty Extension yang digunakan

untuk process encrypt dan decrypt. Akhir sekali, dihanap sistem mi dapat memberikan

pertahanan yang lebih baik kepada penyimpanan data di dalam pengkalan data dan ia

dapat menjadi satu pentahanan yang terakhir kepada data terhadap ancaman-ancaman.

vi

TABLE OF CONTENTS

CHAPTER TITLE PAGE

INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 3

1.3 Objective 4

1.4 Scope 5

2 LITERATURE REVIEW 6

2.1 Introduction to Database 6

2.1.1 Types of Databases 7

2.1.2 Overview of Existing Database Security 10

Technology

2.1.3 Database Security 14

2.2 Introduction to Cryptography 15

2.2.1 Symmetric Cryptography 15

2.2.2 Public-Key Cryptography 15

2.2.3 Hashing Algorithm 16

2.3 Methods of Implementing Cryptography in Database 17

2.3.1 Implementation of Cryptography within 17

Database

2.3.2 Implementation of Cryptography outside 19

Database

2.4 Overview of Current Data Encryption Product 21

2.4.1 Encryptionizer DE 21

2.4.2 RSA BSAFE Encryption Software 22

VII

2.5 Conclusion 23

METHODOLOGY84

3.1 Introduction 24

3.2 Project Method 24

3.2.1 Project Selection and Planning 27

3.2.2 Software Requirements Analysis 28

3.2.3 System Analysis and Design 29

3.2.3.1 Hardware Requirement 34

3.2.3.2 Software Requirement 35

3.2.4 Code Generation 36

3.2.5 Testing 37

3.3 Conclusion 38

4 IMPLEMENTATION 39

4.1 Introduction 39

4.2 Key Vault 41

4.2.1 Local Key Class 41

4.2.2 Local Key Store Class 42

4.3 Key Manifest 47

4.4 Key Tool 53

4.5 Engine 56

4.6 Provider 58

5 RESULTS AND DISCUSSION 59

5.1 Introduction 59

5.2 Results & Discussion 61

5.2.1 Generate Key-Encrypting Key Module 61

5.2.2 Generate New Data Encryption Key Module 61

5.2.3 Search Created Data Encryption Key Module 61

VIII

ix

5.2.4 Search for Data Encryption Key which has 62

"Live" State Module

5.2.5 Replace Data Encryption Key Module 62

5.2.6 Terminate Data Encryption Key Module 62

5.3 User Manual 62

5.4 Advantages & Disadvantages 63

5.4.1 Advantages 63

5.4.2 Disadvantages 64

5.5 Constraints 65

5.6 Recommendations and Further Research 66

6

CONCLUSION 67

REFERENCES 69

APPENDICES A-C 70

LIST OF TABLES

TABLE NO. TITLE

PAGE

3.1 Hardware specification for System Development 34

3.2 Software Requirement for System Development 35

LIST OF FIGURES

FIGURE NO. TITLE PAGE 2.1 Example of database 7 2.2 Example of Flat File database 8 2.3 Example of relational database 9 2.4 Architecture of Security in Microsoft SQL Server 2005 11 2.5 Architecture of RSA Encryption Standalone Software 22

with Protected Database

3.1 System Development Life Cycle 26 3.2 Flow Chart for Encrypting Data from Application 29 3.3 Flow Chart For Decrypting Data from Database 30 3.4 Class Diagram for System Engine in Encrypting and 31

Decrypting Data

3.5 Context Diagram of System 32 3.6 Data Flow Diagram of the proposed System 33 4.1 Local Key Class 41 4.2 generateNewKey() method 42 4.3 key encrypting key table 42 4.4 generateKey() method 43 4.5 encryptKey() method 44 4.6 saveKeyo method 45 4.7 replaceKek() 45 4.8 getLocalKey method 46 4.9 Key Alias class with the declaration of attributes 47

4.10 key manifest table 48 4.11 Acessor and Mutators for the Key Alias class 48

Xi

4.12 getNewAlias() method 49 4.13 populate() method to retrieve Key Alias information 50

4.14 getLiveKeyAlias() method

4.15 save() method to save KeyAlias 52 4.16 Generate key-encrypting key form 53 4.17 Create new data encryption key 54

4.18 Print Created Key using Alias ID 55

4.19 encrypt() method 56 4.20 decryptO method 57 4.21 Provider class 58

XII

LIST OF APPENDICES

APPENDIX TITLE PAGE A Gantt Chart 70 B User Manual 72

C Data Dictionary 79

XIII

CHAPTER 1

INTRODUCTION

This chapter will provide a brief overview of the entire project including the

objective of the project, scope and problem

1.1 Introduction

Nowadays, security issues among server and databases becomes popular as the

dependencies of human on computer devices has been increased rapidly to store data

and company's files. Therefore, its security vulnerability has become a concern to the

company or user.

To help in securing the content of the database, the introduction of encryption

technology to database will be the last line defense for the data after the firewall and

network protection has been broken in by unauthorized personnel. It helps to secure the

content of the database safely by transforming text or files into meaningless characters

which will avoid the third party to read or altar the information in the database.

2

Besides the attack from external user, there is a possibility of internal database

attack happens as database administrator has the right to read or write the content in the

database. To curb this problem, encryption technology will be introduced individually

according to the user in the database. The user manages to select his/her encryption

method to secure data in the database. The user has his/her own password to encrypt

personal details in the database without the acknowledgement of third party.

With this, the data will be secured not only from external attack to the database;

it will also protect the privacy of the user of the database from immoral database

administrator who violates the rights of the user in database.

3

1.2 Problem Statement

Firstly, the existing plain text file in database will become the target of network

culprits to attack the database for either personal usage or as a source to earn profit

illegally. The content maybe deleted or edited by whoever make it through the firewalls

and network protection.

Conventional database allows one encryption method for all the data contained

inside the database. Once the only encryption method is solved by the hackers, all the

data will be translated into meaningful data to be edited or removed.

Thirdly, in a shared database which contained different users, database

administrator have access to data which stored by the users. There is a possibility the

database administrator will explore the data personally without the permission from the

files owner in the database.

4

1.3 Objective

i. To introduce encryption technology into database to help to transform personal

data in database into meaningless character in the database. This will prevent

unauthorized personnel from reading or altering the content of the database.

ii. The encryption method will be a standalone application which will be a middle

tier application to encrypt the data. This will reduce the risk of having the same

encryption at all the database. This will help to protect internal database

administrator from violating the privacy of the users in the database.

iii. To limit database administrator's access to the users' private files. Database

administrator can only access to the database management files and the users'

personal details given by the users. This will prevent the database administrator

from accessing the data without the permission from the user.

5

1.4 Scope

Basically, this system contains several scopes which it can carry out its

operation.

i. This database encryption system will focus on one to one basis which means an

application with a database that it connects to.

ii. Data type for encryption will be focus on plain text alphabet and numerical data.

iii. Type of application using this system is application that saves confidential data

such as credit card numbers in the database.

CHAPTER 2

LITERATURE REVIEW

This chapter briefly explains about the studies of the background of the project to

understand the technology and process involves in the project studied.

2.1 Introduction to Database

The introduction of databases in human is to help human to save the work of

documentation and filing. A database offers a mass amount of space for us to save our

data in a proper and neat method. Its designed is to offer an organized mechanism for

storing, managing and retrieving information. Database uses table which consists of

columns and rows just like how the Microsoft Excel spreadsheet. The column in the

table hold attributes which will determine the value to be inserted into. For the row, it

contains a single record which contributes values to the different columns in the table [1].

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Figure 2.1: Example of database

2.1.1 Types of Databases

There are two (2) main types of databases which are the Flat file database and

Relational database [2].

A Flat file database contains a record per line which consists of plain text or

mixed text and binary file. The fields from the record will be separated by delimiters

such as commas or a fixed length of space. There is no structural relationship between

two different records in the database. An example will be a sheet of paper which

contains a list of names, the owners' addresses and the owners' salary. This is a flat file

database which usually can be done by a typewriter or word processor.

There is a problem using a flat file database because it is very prone to corruption

if it is applied on a semi-active database. This type of database base has no inherent

locking mechanism which will detect a file is being used or modified.

8

An example of flat file database:

I [name, FName Age, Salary ISmith, John, 35 $28 OJDoe

Jane, 28, $325I11ro\, Scott, 41, $265lloward, Shemp, 48,

$359ITaylor, Torn, 22. $250

Figure 2.2: Example of Flat File database

A relational database has its collection of data item organized as a set of table

which has been formally-described. Its data can be accessed from users and

reassembled back in different ways without having the database tables to be reorganized.

The Structured Query Language (SQL) in a relational database is a standard user and

application program interface which is used for interactive queries for information from

a relational database and for gathering data for reports

A relational database is a set of tables which consists of predefined categories

known as column. Each row contains a unique instance/value of data corresponding to

the categories defined by the column. Relational database allows connection between

two different tables with the condition that both of the tables has at least one common

field which it able to relate any two files.

Relational database management system (DBMS) is a management system for

database with the ability to access the data organized in the tables of the database and

relate common field from one record to another. It also has the capability to recombine

the record from different tables which makes it a powerful tool for data usage.

A Relational Data Base AUTI-(R

lit

1711l] Figure 2.3: Example of relational database

10

2.1.2 Overview of Existing Database Security Technology

There are several relational databases technologies nowadays to support different

types of usage and demand in the market. They are built with different architecture and

tools. Here are the overviews of different databases.

Microsoft SQL Server 2005

MS SQL Server is a database management system (DBMS) developed and

marketed by Microsoft. This system is the most important part of Microsoft.NET

technology. MS SQL Server runs exclusively under Microsoft operating systems

Windows 2000, Windows Server 2003, and Window XP [3].

SQL Server secures data with hierarchical encryption layers and a key

management infrastructure. Each layer secures the layer beneath it, using a combination

of certificates, asymmetric keys.

There are two (2) layers:

i. Service Master Key

ii. Database Master Key

I

WiioLvI

O

SQL Server Level

rviC Mast-er K' encrypkcd with OPAPI

4- - - -

Sert',ce (1ster Key

1IDatabase Level - -

Database, Matr Kty

As mm-tri- Itfl Certicaes

SyMmetric Keys

Yrnmiiric Keys,

Data

Figure 2.4: Architecture of Security in Microsoft SQL Server 2005

The top layer, Service Master Key, is encrypted using the Windows data

protection API. Database Master Key depends on the encryption mechanism which

provided by Microsoft.

12

PostgreSQL

PostgreSQL is an open source, Client/Server, relational database. PostgreSQL

offers a unique mix of features that compare well to the major commercial databases

such as Sybase, Oracle and D132. The major advantage of PostgreSQL is that it is open

source - the source code is readable by anyone. It is not owned by a single company

because it is developed, maintained, broken and fixed by a group of volunteer

developers around the world [4].

Important aspects in PostgreSQL:

i. Postgre SQL offers inheritance in the database

ii. Postgre SQL enables user to add new fundamental data types.

iii. Postgre SQL includes support for geometric data types such as point, line

segment, box, polygon, and circle.

Three aspects in PostgreSQL security:

i. Securing the PostgreSQL data files

ii. Securing client access

iii. Granting and denying access to specific tables and specific users

13

Oracle Databases

The Oracle Database consists of a relational database management system

(RDBMS) produced and marketed by Oracle Corporation. As of 2009, Oracle

remains a major presence in database computing.

In order to meet the demands of encryption in database, Oracle8i introduced

a PL/SQL package to encrypt and decrypt stored data.

The package, DBMS _OBFUSCATION TOOLKIT, is provided in both

standard edition and Enterprise Edition Oracle9i [5]. The package currently support

bulk data encryption using Data Encryption Standard (DES) algorithm, and includes

procedures to encrypt (DESEncrypt) and decrypt (DESDecrypt) using DES.

Besides that, Oracle has added support for the triple DES (3DES) encryption • in Oracle8i. Furthermore, it also added support for cryptographic checksumming

using the MD5 algorithm. Cryptography checksums can ensure data intergrity.

14

2.1.3 Database Security

There are different types of attack on the database which are classified as

external and internal attack.

External attack as its name described, its source of attack is from unknown

personnel outside the usage of database such as Internet user or hackers from all

around the world. The administrator takes several measures to curb this problem by

setting up firewalls, intrusion detection systems and authorization before entering

the database. This made it harder for the internet culprit to break in with all these

network security tools [6].

The second attack will be the database internal attack, which has the

advantage of being within the perimeter firewall and having access to information

inside the territory. Many organizations have more worries about external attack

while neglecting the risk of having attack internally. The internal threat is always

• underestimated as its manipulator often is the database administrator. This is

because database administrator has access to everything in the database. They have

the ability to read or edit the content in the database without leavirig a trace behind

[6].

Besides that, the basic of attack to the database can also be categorized into

one-offs and persistent. One-off attack is an attack when the ' attacker achieves his

goals inside the database and vanishes in the air without returning to the database

again. However, persistent attack is an attack where the attacker will return to the

compromised database frequently and launch additional attack to the database.