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Steganography: Data hiding using LSB algorithm

Apr 02, 2015

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A brief discussion about Data security issues and brief

about Cryptography and Steganography.

MSc Information Security and Computer Forensics

INFORMATION SECURITY THROUGH IMAGE STEGANOGRAPHY USING LEAST SIGNIFICANT BIT ALGORITHM

By

NANI KODURI

Master of Science in Information Security and Computer Forensics

University of East London

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

ACKNOWLEDGEMENT:I am extremely satisfied in successfully completing the dissertation for my course MSc Information Security and Computer Forensics. I take this opportunity to thank all my faculties and mentors who took a huge part in my progress. I would especially like to thank Dr. David Preston who helped in completing the dissertation with valuable suggestions and feedback ensuring my direction is correct in my first research project. The UEL library and the Journal Access systems were extremely helpful in providing me with the necessary knowledge to actively engage in the project. I would like to thank my friends for helping me with their expertise in Microsoft .NET technologies for building the steganographic application. Above all, I am grateful to my parents for helping me to pursue this course.

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

TABLE OF CONTENTSABSTRACT CHAPTER 1 1. INTRODUCTION....7 1.1. 1.2. 1.3. 1.4. 1.5. CHAPTER 2 2. LITERATURE REVIEW..12 2.1. INFORMATION SECURITY...12 2.1.1. SECURITY ATTACKS..14 2.2. CRYPTOGRAPHY..17 2.2.1. SYMMETRIC ENCRYPTION ..19 2.2.2. ASYMMETRIC ENCRYPTION...21 2.3. STEGANOGRAPHY...22 PROBLEM STATEMENT......9 OBJECTIVES OF THE STUDY...9 RESEARCH METHOD.....9 SCOPE AND LIMITATIONS...10 THESIS OF THE PROJECT...11

2.3.1. LSB ALGORITHM..24 2.3.2. JSTEG ALGORITHM.26 2.3.3. F5 ALGORITHM.26 2.4. CHAPTER 3 3. DESIGN.29 3.1. 3.2. 3.3. 3.4. ENCRYPTION PHASE...30 TRANSMISSION PHASE...31 DECRYPTION PHASE...32 DATA FLOW DIAGRAMS...32 DIGITAL WATERMARKING...27

3.4.1. CONSTRUCTING DATA FLOW DIAGRAM..34 3.4.2. DATA FLOW DIAGRAM LEVEL 0..34 3.4.3. DATA FLOW DIAGRAM LEVEL 1..350919879 Nani Koduri Page 3

MSc Information Security and Computer Forensics

3.4.4. DATA FLOW DIAGRAM LEVEL 2.....36 3.5. CHAPTER 4 4. EXECUTION38 4.1. HARDWARE AND SOFTWARE REQUIREMENTS.38 ACTIVITY DIAGRAM.....36

4.1.1. MICROSOFT .NET38 4.1.2. CLR..39 4.1.3. WINDOWS FORMS...39 4.1.4. VISUAL C#...............................................................................40 4.2. 4.3. 4.4. FEATURES OF PROPOSED METHOD..41 SYSTEM REQUIREMENTS...41 STEGANOGRAPHY MODULE IMPLEMENTATION.43

4.4.1. ENCRYPTION MODULE..43 4.4.2. DATA TRANSMISSION MODULE..44 4.4.3. DECRYPTION MODULE..45 4.5. CHAPTER 5 5. TESTING.51 5.1. 5.2. 5.3. AIM OF TESTING..52 ARTEFACTS OF TESTING.52 UNIT TESTING..53 SCREENSHOT EXPLANATION46

5.3.1. LIMITATIONS OF UNIT TESTING...54 5.4. 5.5. 5.6. VALIDATION TESTING....54 OUTPUT TESTING54 INTEGRATION TESTING.54

5.6.1. TOP-DOWN APPROACH..55 5.6.2. BOTTOM-UP APPROACH55 5.6.3. UMBRELLA APPROACH..55 5.7. 5.8. USER ACCEPTACE TESTING...56 BLACK BOX AND WHITE BOX TESTING56

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

CHAPTER 6 6. RESULTS AND DISCUSSION..57 CHAPTER 7 7. CONCLUSION AND FUTURE WORK59

8. REFERENCES.60

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

ABSTRACT:The rapid development of data transfer through internet made it easier to send the data accurate and faster to the destination. There are many transmission media to transfer the data to destination like e-mails; at the same time it is may be easier to modify and misuse the valuable information through hacking. So, in order to transfer the data securely to the destination without any modifications, there are many approaches like cryptography and steganography. This paper deals with the image steganography as well as with the different security issues, general overview of cryptography, steganography and digital watermarking approaches and about the different steganographic algorithms like Least Significant Bit (LSB) algorithm, JSteg, F5 algorithms. It also compares those algorithms in means of speed, accuracy and security. This paper gives a brief idea about the new image steganographic approach that make use of Least Significant Bit (LSB) algorithm for embedding the data into the bit map image (.bmp) which is implemented through the Microsoft .NET framework.

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

CHAPTER 1 1. INTRODUCTIONIn the current trends of the world, the technologies have advanced so much that most of the individuals prefer using the internet as the primary medium to transfer data from one end to another across the world. There are many possible ways to transmit data using the internet: via e-mails, chats, etc. The data transition is made very simple, fast and accurate using the internet. However, one of the main problems with sending data over the internet is the security threat it poses i.e. the personal or confidential data can be stolen or hacked in many ways. Therefore it becomes very important to take data security into consideration, as it is one of the most essential factors that need attention during the process of data transferring. Data security basically means protection of data from unauthorised users or hackers and providing high security to prevent data modification. This area of data security has gained more attention over the recent period of time due to the massive increase in data transfer rate over the internet. In order to improve the security features in data transfers over the internet, many techniques have been developed like: Cryptography, Steganography and digital watermarking. While Cryptography is a method to conceal information by encrypting it to cipher texts and transmitting it to the intended receiver using an unknown key, Steganography provides further security by hiding the cipher text into a seemingly invisible image or other formats. According to Johnson et al., (2001), Steganography is the art of hiding and transmitting data through apparently innocuous carriers to conceal the existence of data. The level of visibility is decreased using many hiding techniques in Image Modelling like LSB Manipulation, Masking and filtering. These techniques are performed by different steganographic algorithms like F5, LSB, JSteg etc. and the act of detecting the information hidden through these algorithms is called Steganalysis. Cryptography is the art of science used to achieve security by encoding the data to transform them into non readable formats so that unauthorized users cannot gain access to it.0919879 Nani Koduri

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MSc Information Security and Computer Forensics

The encoded text is known as Cipher text and this technique is known as encryption and this process is reversed with authorised access using the decryption technique, in which the encoded data is decoded into readable format (Kahate, 2008). Steganography and Cryptography are closely related constructs. The hidden or embedded image, audio or a video files act as carriers to send the private messages to the destination without any security breach. Steganography techniques can be implemented on various file formats such as audio (.mp3, .wmv., etc.), video (.mpeg, .dat, etc.) and images (.jpeg, .bmp, etc.). However, the images are the most preferred file format for this technique. At present, there are a lot of algorithms that help in executing the steganography software. These tools are (Krenn, 2004). Digital watermarking is described as one of the possibilities to close the gap between copyright issues and digital distribution of data. It is mainly based on Steganographic techniques and enables useful safety mechanisms (Jeffrey, 2008). It acts as a very good medium for copyright issues as it embeds a symbol or a logo in the form of a watermark, which cannot be altered manually. One critical factor to be kept in mind when using steganography is to prevent any further alterations to the originality of the image after embedding the data. Whenever the image with the secret data is transmitted over the internet unauthorised parties may want to hack the data hidden over the image. So, if the originality of the image has been changed then it will be easier to hack the information by unauthorised persons. In order to improve the security, the Digital watermarks are predominantly inserted as transformed digital signal into the source data using key based embedding algorithm and pseudo noise pattern. This technique has also found big use in the notorious hands of terrorists and the September 2001 Twin tower attacks of the USA are predominantly associated with the communications using steganography. The Steganalysis aims at discovering and decrypting the suspected data transferred with the use of the available algorithms.

0919879 Nani Koduri

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MSc Information Security and Computer Forensics

1.1 PROBLEM STATEMENT:The aim of the project is to encrypt the data i.e., hide the data over an image using different steganographic algorithms and to compare those algorithms in the context of speed, quality of concealing and the use of watermarks and to describe their functionality in data security. 1.2 OBJECTIVES OF THE STUDY:

In my project I primarily concentrated on the data security issues when sending the data over the network using steganographic techniques. The main objectives of the project are Overview of different steganographic algorithms and comparing them in means of speed and quality of hiding. Testing the efficiency and accuracy of hiding the data through algorithms using different software. 1.3 RESEARCH METHOD:

In this project, I use a method of encrypting the text and audio file