Image and Audio Steganography
SUBMITTED BY
[Student Name]
[Seat No.]
DATE OF SUBMISSION
[If a revised proposal is submitted, the date should be changed accordingly]
Under the guidance of Lionel Faleiro
Submitted in partial fulfillment of the requirements for qualifying M.C.A Semester VI Examination
INSTITUTE OF DISTANCE AND OPEN LEARNING
UNIVERSITY OF MUMBAI
DR. SHANKAR DAYAL SHRAMA BHAVAN,
INSTITUTE OF DISTANCE AND OPEN LEARNING
UNIVERSITY OF MUMBAI, IDE BUILDING, VIDYANAGARI, MUMBAI-98PROJECT CERTIFICATE
This is to certify that the Project titled
________________________________________by Mr./Ms.
__________________________________________________________________ Seat No _________________ in partial fulfillment for M.C.A Degree Examination in Semester VI for the academic year 2014-2015 has been found satisfactory. This report had not been submitted for any other examination and does not form part of any other course undergone by the candidate.
Signature Signature Signature
Faculty in Charge External Examiner Coordinator – M.C.A (IDOL)
Guided By Examined By Certified By
Acknowledgement
It has indeed been a great privilege for me to have Mr. Lionel Faleiro, Department of Computer Science, I.D.O.L., University of Mumbai, as my mentor for this project.
His guidance and constant encouragement are the motive force behind this project work. I take this opportunity to express my utmost gratitude to him. I am also indebted to him for his timely and valuable advice.
Synopsis
on
Image and Audio Steganography
Submitted for partial fulfillment of award of
MCA Semester VI Examination
Statement about the Problem
Steganography is the practice of hiding private or sensitive information within something that appears to be nothing out to the usual. Steganography is often
confused with cryptology because the two are similar in the way that they both are used to protect important information. The difference between two is that
steganography involves hiding information so it appears that no information is hidden at all. If a person or persons views the object that the information is hidden inside of he or she will have no idea that there is any hidden information, therefore the person will not attempt to decrypt the information.
What steganography essentially does is exploit human perception, human senses are not trained to look for files that have information inside of them, although this software is available that can do what is called Steganography. The most common use of steganography is to hide a file inside another file.
Why is the particular topic is chosen?
Through out history Steganography has been used to secretly communicate information between people.
Some examples of use of Steganography is past times are:
1. During World War 2 invisible ink was used to write information on pieces of paper so that the paper appeared to the average person as just being blank pieces of paper. Liquids such as milk, vinegar and fruit juices were used, because when each one of these substances are heated they darken and become visible to the human eye.
2. In Ancient Greece they used to select messengers and shave their head, they would then write a message on their head. Once the message had been written the hair was allowed to grow back. After the hair grew back the messenger was sent to deliver the message, the recipient would shave off the messengers hair to see the secrete message.
Now in today’s electronic world the message is sent over E media. So there should be a necessity of new steganography technique which will defend against interception attack.
Why This Steganography?
This technique is chosen, because this system includes not only imperceptibility but also un-delectability by any steganolysis tool.
Objective:-• Requirement of this steganography system is that the hider message carried by stego-media should not be sensible to human beings.
• The other goal of steganography is to avoid drawing suspicion to the existence of a hidden message.
This approach of information hiding technique has recently become important in a number of application areas
Project Scope:
• The scope of the project is to limit unauthorized access and provide better security during message transmission. To meet the requirements, I use the simple and basic approach of steganography.
• In this project, the proposed approach finds the suitable algorithm for
embedding the data in an image / audio using steganography which provides the better security pattern for sending messages through a network.
User needs to run the application. The user has two tab options – encrypt and decrypt. If user select encrypt, application give the screen to select image file, information file and option to save the image file. If user select decrypt, application gives the screen to select only image file and ask path where user want to save the secrete file.
This project has two methods – Encrypt and Decrypt.
In encryption the secrete information is hiding in with any type of image file.Decryption is getting the secrete information from image file. We will make use of LSB algorithm for this process.
LSB Algorithm:
• LSB (Least Significant Bit) substitution is the process of adjusting the least significant bit pixels of the carrier image.
• It is a simple approach for embedding message into the image.
• The Least Significant Bit insertion varies according to number of bits in an image.
• For an 8 bit image, the least significant bit i.e., the 8th bit of each byte of the image is changed to the bit of secret message.
• For 24 bit image, the colors of each component like RGB (red, green and blue) are changed.
• LSB is effective in using BMP images since the compression in BMP is lossless
For digital audio files the techniques are:
a. LSB Coding b. Phase Coding
c. Parity Coding d. Spread Sprectrum
Encryption Process
IMAGE FILE INFORMATION FILE
BMP FILE
Decryption Process
BMP FILE
INFORMATION FILE IMAGE FILE
Limitations of the Software:
This project has an assumption that is both the sender and receiver must have shared some secret information before imprisonment. Pure steganography means that there is none prior information shared by two communication parties.
• In the present world, the data transfers using internet is rapidly growing because it is so easier as well as faster to transfer the data to destination. So, many individuals and business people use to transfer business documents, important information using internet.
• Security is an important issue while transferring the data using internet because any unauthorized individual can hack the data and make it useless or obtain information un- intended to him.
Software Environment
Operating System : Window XP
Development Environment : MS Visual Studio .Net Framework 4.5
Languages : C#.Net
Hardware Environment
Processor : Intel® Core™ i3-4005U CPU
@ 1.70 GHz
RAM : 8 GB
Hard Disk : 250 GB
Mother Board : Intel chipset board
Mouse : Logitech optical mouse
Key Board : 104 keys keyboardConclusion:-Steganography is a really interesting subject and outside of the mainstream cryptography and system administration that most of us deal with day after day.
Steganography can be used for hidden communication. We have explored the limits of steganography theory and practice. We printed out the enhancement of the image steganography system using LSB approach to provide a means of secure communication. A stego-key has been applied to the system during embedment of the message into the cover image.
This steganography application software provided for the purpose to how to use any type of image formats to hiding any type of files inside their. The master work of this application is in supporting any type of pictures without need to convert to bitmap, and lower limitation on file size to hide, because of using maximum memory space in pictures to hide the file.
Bibliography
Websites
Following websites are referring to create this project reports.
http://www.asp.net http://www.asp123.com http://www.wikipedia.org
Books
Following books and ebook are used to complete this project reports.
Mastering C# (Paperback)
Professional C#, 2nd Edition (Paperback)
Professional ASP.NET (Paperback)
MCAD/MCSD Self-Paced Training Kit: Developing Web Applications with Microsoft® Visual Basic® .NET and Microsoft Visual C#® .NET, Second Edition
Index
2. Theoretical Background a. Analysis of Digital Image b. Analysis of Digital Audio 3. Definition of the Problem 4. System Analysis and Design
a. Context Diagram b. Data Flow Diagram c. Encoding
d. Decoding e. Algorithms
5. Software and Hardware Environment a. About the Software and Methodology b. Functions
6. System Implementation 7. System Maintenance 8. Cost and Benefit Analysis 9. Project Life Cycle
a. Input and Output Screen Design b. Process involved
c. Methodology used for testing: d. Source code e. User Manual
Annexure
1. References Bibliography Websites 2. KeywordsObjective and Scope of the Project
The objective of steganography is covert communication. So, a fundamental requirement of this steganography system is that the hider message carried by stego-media should not be sensible to human beings.
The other objective of steganography is to avoid drawing suspicion to the existence of a hidden message. This approach of information hiding technique has recently became important in a number of application area
This project has following objectives:
• To product security tool based on steganography techniques.
• To explore techniques of hiding data using encryption module of this project • To extract techniques of getting secret data using decryption module.
Steganography sometimes is used when encryption is not permitted. Or, more commonly, steganography is used to supplement encryption. An encrypted file may still hide information using steganography, so even if the encrypted file is deciphered, the hidden message is not seen
Scope of Steganography
Steganography is a very interesting and advantageous science these days and has following uses:
Digital Watermarking
To protect a copyright on information. Photo collections, sold on CD, often have hidden messages in the photos which allow detection of unauthorized use. The same technique applied to DVDs is even more effective, since the industry builds DVD recorders to detect and disallow copying of protected DVDs.
The simplest and oldest are used in map making, where cartographers
sometimes add a tiny fictional street to their maps, allowing them to prosecute copycats.
A similar trick is to add fictional names to mailing lists as a check against unauthorized resellers.
Steganography doesn't just apply to written forms of communication. Radio and TV messages, from World War II to today, can be used to hide coded or hidden messages. Some government sources suspect that Osama bin Laden's pre-recorded videos that are re-played on TV stations around the world contain hidden messages.
Even biological data, stored on DNA, may be a candidate for hidden messages, as biotech companies seek to prevent unauthorized use of their genetically engineered material. The technology is already in place for this: three New York researchers successfully hid a secret message in a DNA sequence and sent it across the country.
Steganography can also be used to allow communication within an underground community.
Steganography is used by some modern printers, including HP and Xerox brand color laser printers. Tiny yellow dots are added to each page. The dots are barely visible and contain encoded printer serial numbers, as well as date and time stamps.
Overview
The word steganography comes from the Greek “Seganos”, which mean covered or secret and – “graphy” mean writing or drawing. Therefore, steganography mean, literally, covered writing. It is the art and science of hiding information such its presence cannot be detected and a communication is happening. A secrete information is encoding in a manner such that the very existence of the information is concealed. Paired with existing communication methods, steganography can be used to carry out hidden exchanges.
The main goal of this projects it to communicate securely in a completely undetectable manner and to avoid drawing suspicion to the transmission of a hider data. There has been a rapid growth of interest in steganography for two reasons:
The publishing and broadcasting industries have become interested in techniques for hiding encrypted copyright marks and serial numbers in digital films, audio recordings, books and multimedia products
Moves by various governments to restrict the availability of encryption services have motivated people to study methods by which private messages can be embedded in seemingly innocuous cover messages.
The basic model of steganography consists of Carrier, Message and password. Carrier is also known as cover-object, which the message is embedded and serves to hide the presence of the message.
Cover-object, C
Message, M
Stego-key, K
F(X,M,K)
Stego Object, Z
Basically, the model for steganography is shown on following figure:
Message is the data that the sender wishes to remain it confidential. It can be plain text, ciphertext, other image, or anything that can be embedded in a bit stream such as a copyright mark, a covert communication, or a serial number. Password is known as
stego-key, which ensures that only recipient who know the corresponding decoding key
will be able to extract the message from a cover-object. The cover-object with the secretly embedded message is then called the Stego-object.
Recovering message from a stego-object requires the cover-object itselt and a corresponding decoding key if a stego-key was used during the encoding process. The original image may or may not be required in most applications to extract the message. There are several suitable carriers below to be the cover-object:
Network protocols such as TCP, IP and UDP
Audio that using digital audio formats such as wav, midi, avi, mpeg, mpi and voc
File and Disk that can hides and append files by using the slack space
Images file such as bmp, gif and jpg, where they can be both color and gray-scale.
In general, the information hiding process extracts redundant bits from cover-object. The process consists of two steps:
Identification of redundant bits in a cover-object. Redundant bits are those bits that can be modified without corrupting the quality or destroying the integrity of the cover-object.
Embedding process then selects the subset of the redundant bits to be replaced with data from a secret message. The stego-object is created by replacing the selected redundant bits with message bits.
Steganography vs Cryptography:
Basically, the purpose of cryptography and steganography is to provide secret communication. However, steganography is not the same as cryptography. Cryptography hides the contents of a secrete message from a malicious people, whereas steganography even conceal the existence of the message. In cryptography, the system is broken when the attacker can read the secret message. Breaking a steganography system need the attacker to detect that steganography has been used. It is possible to combine the techniques by encrypting message using cryptography and then hiding the encrypted message using steganography. The resulting stego-image can be transmitted without revealing that secret information is being exchanged.
.S
Functions
THEORETICAL BACKGROUND
ANALYSIS OF DIGITAL IMAGE
An image file is merely a binary file containing a binary representation of the color or light intensity of each picture element (pixel) comprising the image.
Images typically use either 8-bit or 24-bit color.
When using 8-bit color, there is a definition of up to 256 colors forming a palette for this image, each color denoted by an 8-bit value.
A 24-bit color scheme, as the term suggests, uses 24 bits per pixel and provides a much better set of colors. In this case, each pixel is represented by three bytes, each byte representing the intensity of the three primary colors red, green, and blue (RGB), respectively. The color orange, for example, would be displayed with red set to 100% , green set to 50% and no blue .
The size of an image file, then, is directly related to the number of pixels and the granularity of the color definition. A typical 640x480 pix image using a palette of 256 colors would require a file about 307 KB in size (640 • 480 bytes), whereas a 1024x768 pix high-resolution 24-bit color image would result in a 2.36 MB file (1024 • 768 • 3 bytes).
To avoid sending files of this enormous size, a number of compression schemes have been developed over time, notably Bitmap (BMP), Graphic Interchange Format (GIF), and Joint Photographic Experts Group (JPEG) file types. Not all are equally suited to steganography, however.
GIF and 8-bit BMP files employ what is known as lossless compression, a scheme that allows the software to exactly reconstruct the original image. JPEG, on the other hand, uses lossy compression, which means that the expanded image is very nearly the same as the original but not an exact duplicate. Lossless compression is much better suited to applications where the integrity of the original information must be maintained, such as steganography. While JPEG can be used for stego applications, it is more common to embed data in GIF or BMP files.
The simplest approach to hiding data within an image file is called Least Significant Bit (LSB) insertion. In this method, we can take the binary representation of the hidden_data and overwrite the LSB of each byte within the cover_image. If we are using 24-bit color, the amount of change will be minimal and indiscernible to the human eye. As an example, suppose that we have three adjacent pixels (nine bytes) with the following RGB encoding:
10010101 00001101 11001001 10010110 00001111 11001010 10011111 00010000 11001011
Now suppose we want to "hide" the following 9 bits of data (the hidden data is usually compressed prior to being hidden): 101101101. If we overlay these 9 bits over the LSB of the 9 bytes above, we get the following (where bits in bold have been changed):
10010101 00001100 11001001 10010111 00001110 11001011
10011111 00010000 11001011
Note that we have successfully hidden 9 bits but at a cost of only changing 4, or roughly 50%, of the LSBs.
A 640x480 pixel image, the size of a small computer monitor, can hold over 400,000 characters. That's a whole novel hidden in one modest photo! This poject involves following formats of images:
Bitmap Images
(.bmp)
Joint Photographic Experts Group
(.jpg)
Portable Network Graphics
(.png)
Tagged Image File Format
(.tif)
BMP Image File Format
File Header
Data
Size(Bytes)
File Type(BM in case of BMP files)
2
File Size
4
Reserved Byte(Always 0)
1
Reserved Byte(Always 0)
1
Bf of Bits
Size of Info Header
4
Width of Bitmap
2
Height of Bitmap
2
No of planes(1 for BMP)
1
Bit Count(Bits/Pixel, Must be 1, 4, 8, 24)
1
Type of Compression used(none)
2
Size of Image Data in Bytes
2
Horizontal Resolution in Pixels/Meter
2
Vertical Resolution in Pixels/Meter
2
No of Color’s Indexes Used
2
Important Color Indexes
2
Reading Pixel Values
Data
Size(Bytes)
R(Red)
1
B(Blue)
1
G(Green)
1
ANALYSIS OF DIGITAL AUDIO
Digital audio differs from traditional analog sound in that it is a discrete rather than continuous signal. A discrete signal is created by sampling a continuous analog signal at a specified rate. For example, the standard sampling rate for CD digital audio is about 44kHz. The following figure illustrates a continuous analog sound wave being sampled to produce digital audio. Note the sinusoidal nature of a sound wave.
We emphasize the discrete nature of a digital signal in the diagram. However, standard sampling rates are usually set at a level where the resultant digital signal is visually indistinguishable from the original analog signal.
Digital audio is stored on a computer as a sequence of 0's and 1's. With the right tools, it is possible to change the individual bits that make up a digital audio file. Such precise control allows changes to be made to the binary sequence that are not
discernible to the human ear. The secret message is embedded by slightly altering the binary sequence of a sound file.
The key innovation in recent years was to choose an innocent looking cover that
contains plenty of random information, called white noise. You can hear white noise as a the nearly silent hiss of a blank tape playing. The secret message replaces the white noise, and if done properly it will appear to be as random as the noise was. Thus the basic design principle of steganographic systems is “replacing high entropy noise with a high entropy secret transmission” .
Wave File Format
Wave Header
Data
Size(Bytes)
Header Name(RIFF) 4 File Size 4 Format Name(wave) 4 Key Word(fmt) 4 Channels(Mono = 1, Stereo = 2) 1 Frequency 4Blank(Less Important Data) 6
Bit Resolution 1
Blank(Less Important Data) 12
Wave Data
Data
Size(Bytes)
Sound Length 1
Frequency 1
Definition of the Problem
The former consists of linguistic or language forms of hidden writing. The later, such as invisible ink, try of hide messages physically. One disadvantage of linguistic
steganography is that users must equip themselves to have a good knowledge of linguistry. In recent years, everything is trending toward digitization. And with the
development of the internet technology, digital media can be transmitted conveniently over the network. Therefore, messages can be secretly carried by digital media by using the steganography techniques, and then be transmitted through the internet rapidly
Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the internet. For hiding secret information in images, there exists a large variety of steganography techniques some are more complex than others and all of them have respective strong and weak points.
So we prepare this application, to make the information hiding more simple and user friendly.
System Analysis and Design
System Analysis
Existing System:
Now a days, several methods are used for communicating confidential messages for defense purposes or in order to ensure the privacy of communication between two parties. So we go for hiding information in ways that prevent its detection.
Some of the methods used for privacy communication are the use of invisible links; covert channels are some of existing systems that are used to convey the messages. Since at present everything is done manually, it is having a lot of drawbacks. The major Drawback of the present system is the bulk amount of physical volume of the data making information search and retrieval is tedious Process. There are chances for damage of papers containing information. So this process is time consuming process. Drawbacks:
• Increased time
• Low accuracy
• High labour charges • Increased uncertainty • Data security is less
Proposed System:
The proposed system uses Image file as a carrier medium which add another step in security. The objective of the newly proposed system is to create a system that makes it very difficult for an opponent to detect the existence of a secret message by encoding carrier medium as a function of some secret key and that remains as the advantage of this system.
This system have several advantages over the existing system. They are 1. Data security is high.
2. It avoids data redundancy and ensures data integrity. 3. It doesn’t take more labour time.
Feasibility Study:
The feasibility of the project is analyzed in this phase and business proposal is set forth with a very general plan for the project and some cost estimates. During system analysis the feasibility study of the proposed system is to be carried out. This is to ensure that the proposed system is not a burden to the company. For feasibility analysis, some understanding of the major requirements for the system is essential.
Three key considerations involved in the feasibility analysis are 1. Economical feasibility
2. Technical feasibility 3. Social feasibility
1. Economical feasibility:
This study is carried out to check the economic impact for the system will have on the organization. The amount of fund that the company can pour into the research and development of the system is limited. The expenditures must be justified. Thus the developed system as well within the budget and this was achieved ,because most of the technologies used are freely available. Only the customized products had to be
purchased.
2. Technical feasibility:
If study is carried out to check about the technical requirements of the system. Any system developed must not have a high demand on the available technical resources. This will lead to high demands on the available technical resources. This will lead to high demands being placed on the client. The developed system must have a modern
requirement, as only minimal or null changes are required for implementing this system.
3. Social feasibility:
The aspect of study is to check the level of acceptance of the system by the user. This includes the process of training the user to use the system efficiently. The user must not feel threatened by the system, instead must accept as a necessity. The level of
acceptance by the users solely depends on the methods that are employed to educate the user about the system and to make him familiar with it. His level of confidence must be raised ,so that also able to make some constructive criticism, as he is the final user of the system.
CONTEXT DIAGRAM
PLAIN TEXT OR
COVER MEDIUM TEXT FILE STEGNO
KEY (Image or Audio File) (Text to be Hidden)
STEGNO-ENCODING TOOL STEGNO MEDIUM STEGNO-DECODING TOOL
.DAT FILE CONTAINING HIDDEN TEXT
DATA FLOW DIAGRAM
ENCODING
PLAIN STEGNO KEY TEXT Vigenere CipherEncripted Arithmeticcoding Text Conversion into ASCII form Key Conversion Information into 8-bit form Bit Stream
Read the Audio in
Using Key Frequency Values
in Byte form Information Encode
Bit Stream in the
COVER Bit/Byte Stream of
Cover Medium MEDIUM
Read the Image in RGB values of pixel in Bit form
Resultant Bit/ Byte Stream
STEGNO MEDIUM
DECODING
STEGNO Arithmetic Key
coding
KEY Information
Read the Audio in
Frequency Values Using Key
in Byte form Information
STEGNO Decode BitStream in the
MEDIUM Bit/Byte Stream
Read the Image in RGB values of pixel in Bit form
Bit Stream of Hidden Text Conversion into 8-bit form Conversion into ASCII Form Vigenere Encripted Cipher Text ORIGINAL TEXT
ALGORITHMS
ENCODINGLeast significant bit (LSB) coding is the simplest way to embed information in a digital Image or Audio file. By substituting the least significant bit of each sampling point in Audio and each pixel in Image with a binary message, LSB coding allows for a large amount of data to be encoded.
The following diagram illustrates how the message 'HEY' is encoded in a 16-bit CD quality sample using the LSB method:
ALGORITHM FOR ENCODING
STEP 1. //Information from Stegno Key Input the key in string datatype;
//Apply Arithmetic coding to the string key float num = Arithmetic_coding( key); num=num*100;
x=10*(1st digit of num); y=10*(2st digit of num); STEP 2. //converting Plain Text into Bit Stream
//Input Text to be hidden in string datatype; string plaintext;
//apply encription algorithm on this string string ciphertext = Vigenere_cipher(plaintext); convert ciphertext ASCII form;
convert ASCII form Bit_stream;
STEP 3. //Hiding bitstream of input text in Image or Audio file int n = length(plaintext);
//HIDING IN IMAGE FILE
get_resolution( image ) pxq; if (p==odd) p=p-1; if(q==odd) q=q-1;
R value of 1x1 pixel = n; int g =1; int h=1;
int m= bit lodation in Bit_stream; char C= R or G or B; for(int i=0;i<8n;i++)
{
If (m%3==1) C=R; If (m%3==1) C=G; If (m%3==1) C=B
Least significant digit of C value of (g+x)x(h+y) th pixel = Bit_stream[i];
g = g+x; h = h+y; }
//HIDING IN AUDIO FILE
string audio_stream= sampled audio Byte_stream; audio_stream[0]= n;
for(int i=0;i<8n;i++) {
If (Bit_stream[i]==0) audio_stream[i++]=audio_stream[i++] AND “11111110”;
If (Bit_stream[i]==1) audio_stream[i]=audio_stream[i] OR “00000001”;
ALGORITHM FOR DECODING
STEP 1. //Information from Stegno Key Input the key in string datatype;
//Apply Arithmetic coding to the string key float num = Arithmetic_coding( key); num=num*100;
x=10*(1st digit of num); y=10*(2st digit of num); //from IMAGE file
STEP 2. //read stegno image
int n= R value of 1x1 pixel int g=0; int h=0;
STEP 3. for(int i=1; i<=n;i++) { g=g+x; h=h+y; string Bit_stream; char C; If (i%3==1) C=R; If (i%3==1) C=G; If (i%3==1) C=B;
Bit_stream[i--]=least significant digit of C value of (gxh) pixel
}
STEP 2. //read stegno audio
string audio_stream= sampled stegno audio Byte_stream; int n = audio_stream[0];
STEP 3. for(int i=1;i<8n;i++) {
Bit_stream[i]=least significant digit of audio_stream[i]; }
STEP 4. //converting Bit Stream into Plain Text string ciphertext ;
convert Bit_stream ASCII form; convert ASCII form ciphertext; //apply dencription algorithm on this string
Vigenere Cipher
Plain text: ATTACKATDAWN Key: LEMONLEMONLE
Cipher text: LXFOPVEFRNHR
The person sending the message chooses a keyword and repeats it until it matches the length of the plaintext, for example, the keyword "LEMON" makes: Key: LEMONLEMON
Software & Hardware Environment
Software Environment
Operating System : Window XP
Development Environment : MS Visual
Studio .Net Framework 4.5
Languages : C#.Net
Hardware Environment
Processor : Intel®
Core™ i3-4005U CPU @ 1.70 GHz
RAM : 8 GB
Hard Disk : 250 GB
Mother Board : Intel
chipset board
Mouse : Logitech
optical mouse
Key Board : 104 keyskeyboard
About the software and Methodology
What is .Net?
When .NET was announced in late 1999, Microsoft positioned the technology as a platform for building and consuming Extensible Markup Language (XML) Web services. XML Web services allow any type of application, be it a Windows- or browser-based application running on any type of computer system, to consume
data from any type of server over the Internet. The reason this idea is so that this is the way in which the XML messages are transferred: over established standard protocols that exist today. Using protocols such as SOAP, HTTP, and SMTP, XML Web services make it possible to expose data over the wire with little or no modifications to your existing code.
Figure presents a high-level overview of the .NET Framework and how XML Web services are positioned.
Stateless XML Web services model
Since the initial announcement of the .NET Framework, it's taken on many new and different meanings to different people. .NET developer creates great environment for robust distributed
applications. The role of IT manager,to deployment of applications to end users, tighter security, and simpler management. For the above statement, we need to get a grip on what the .NET Framework consists of, and how it's truly a revolutionary step forward for application architecture, development, and
.NET Framework
We are familiar with the major goals of the .NET Framework, and its architecture. As the .NET Framework lays on top of the operating system, which can be a few different compound of Windows .NET is a system application that needs a Windows operating system. Conceptually, the CLR and the JVM are similar in that they are both runtime infrastructures that abstract the underlying platform differences. However, while the JVM officially supports only the Java language, the CLR supports any language that can be represented in its Common Intermediate Language (CIL). The JVM executes byte code, so it can, in principle, support many languages,. Unlike Java's byte code,
though CIL is never interpreted. Conceptual difference between the two infrastructures is that Java code runs on any platform with a JVM, whereas .NET code runs only on platforms that support the CLR.
The Common Language Runtime
The heart of the .NET Framework is the common language runtime. The common language runtime is responsible for providing the execution environment that code written in a .NET language runs under. The common language runtime can be compared to the Visual Basic 6 runtime, except that the common language runtime is designed to handle all .NET languages, not
any one. The mention below are list describes the benefits of common language runtime:
• Automatic memory management
• Cross-language debugging
• Cross-language exception handling • Full support for component versioning • Access to legacy COM components
• XCOPY deployment
• Robust security model
You might expect all those features, but this has never been possible using Microsoft development tools. Figure shows where the common language runtime fits into the .NET Framework.
Fig. The Common Language Runtime
Note
Code written using a .NET language is known as managed code. Code that uses anything but the common language runtime is
known as unmanaged code. The common language runtime provides a managed execution environment for .NET code, whereas the individual runtimes of non-.NET languages provide an unmanaged execution environment.
Inside the Common Language Runtime
The common language runtime enables code running in its execution environment to have features such as security, versioning, memory management and exception handling because of the way .NET code actually executes. When you compiled Visual Basic 6 forms applications, you had the ability to compile down to native node or p-code.
When you compile your applications in .NET, you aren't creating anything in native code. When you compile in .NET, you're converting your code—no matter what .NET language you're using—into an assembly made up of an intermediate language called Microsoft Intermediate Language.
Note
The file format for the integrated language is known as PE (portable executable) format, which is a standard format for processor-specific execution. When a user or another component executes your code, a process occur called just-in-time (JIT) compilation, and it's at this point that the IL is converted into the specific machine language of the processor it's executing on. This makes it very easy to port a .NET application to any type of operating system on any type of processor because the IL is simply waiting to be consumed by a JIT compiler.
When the IL code is JITted into machine-specific language, it does so on an as-needed basis. If your assembly is 10MB and the user is only using a fraction of that 10MB, only the required IL and its dependencies are compiled to machine language. This makes for a very efficient execution process. But during this execution, how does the common language runtime make sure that the IL is correct? Because the compiler for each language creates its own IL, there must be a process that makes sure what's compiling won't corrupt the system. The process that validates the IL is known as verification. Figure 3.5 demonstrates the process the IL goes through before the code actually executes.
Fig. The JIT process and verification
When code is JIT compiled, the common language runtime checks to make sure that the IL is correct. The rules that the common language runtime uses for verification are set forth in the Common Language Specification (CLS) and the Common Type System (CTS).
The .NET Framework Class Library
The second most important piece of the .NET Framework is the .NET Framework class library (FCL). As you've seen, the common language runtime handles the dirty work of actually running the code you write. But to write the code, you need a foundation of available classes to access the resources of the operating system, database server, or file server. The FCL is made up of a hierarchy of namespaces that expose classes, structures, interfaces, enumerations, and delegates that give you access to these resources.
The Structure of a .NET Application
To understand how the common language runtime manages code execution, you must examine the structure of a .NET application. The primary unit of a .NET application is the assembly. An assembly is a self-describing collection of code,
resources, and metadata. The assembly manifest contains information about what is contained within the assembly.
The assembly mainfest provides:
• Identity information, such as the assembly’s name and version number
• A list of all types exposed by the assembly
• A list of other assemblies required by the assembly
• A list of code access security instructions, including permissions required by the assembly and permissions to be denied the assembly
Each assembly has one and only one assembly manifest, and it contains all the description information for the assembly. However, the assembly manifest can be contained in its own file or within one of the assembly’s modules.
Compilation and Execution of a .NET Application
When you compile a .NET application, it is not compiled to binary machine code; rather, it is converted to IL. This is the form that your deployed application takes—one or more assemblies consisting of executable files and DLL files in IL form. At least one of these assemblies will contain an executable file that has been designated as the entry point for the application.When execution of your program begins, the first assembly is loaded into memory. At this point, the common language runtime examines the assembly manifest and determines the requirements to run the program. It examines security permissions requested by the assembly and compares them with the system’s security policy. If the system’s security policy does not allow the requested permissions, the application will not run. If the application passes the system’s security policy, the common ¬language runtime executes the code. It creates a process for the application to run in and begins application execution. The .NET Framework base class library contains the base classes that provide many of the services and objects you need when writing your applications. The class library is organized into namespaces. A namespace is a logical grouping of types that
perform related functions. Namespaces are logical groupings of related classes. The namespaces in the .NET base class library are organized hierarchically. The root of the .NET Framework is the system namespace. Other namespaces can be accessed with the period operator. A typical namespace construction appears as follows:
System System.Data
System.Data.SQLClient
.Net Namespaces
Table 1-1. Representative .NET Namespaces
Namespace Description
System This namespace is the root for many of the low-level types required by the .NET Framework. It is the root for primitive data types as well, and it is the root for all the other namespaces in the .NET base class library.
System.Collections This namespace contains classes that represent a variety of different
container types, such as ArrayList, SortedList, Queue, and Stack. You also can find abstract classes, such as CollectionBase, which are useful for implementing your own collection functionality.
Table 1-1. Representative .NET Namespaces
Namespace Description
involved in component creation and containment, such as attributes, type converters, and license providers.
System.Data This namespace contains classes
required for database access and manipulations, as well as additional namespaces used for data access. System.Data. Common This namespace contains a set of
classes that are shared by the .NET managed data providers.
System.Data.OleDb This namespace contains classes that make up the managed data provider for OLE DB data access.
System.Data.SQLClient This namespace contains classes that are optimized for interacting with Microsoft SQL Server.
System.Drawing This namespace exposes GDI+
functionality and provides classes that facilitate graphics rendering.
System.IO In this namespace, you will find types for handling file system I/O.
System.Math This namespace is home to common
mathematics functions such as extracting roots and trigonometry. System.Reflection This namespace provides support for
Table 1-1. Representative .NET Namespaces
Namespace Description
obtaining information and dynamic creation of types at runtime.
System.Security This namespace is home to types dealing with permissions,
cryptography, and code access security.
System.Threading This namespace contains classes that facilitate the implementation of
multithreaded applications. System.Windows.Forms This namespace contains types
involved in creating standard Windows applications. Classes that represent forms and controls reside here as well.
Introduction to Object-Oriented Programming
Programming in the .NET Framework environment is done with objects. Objects are programmatic constructs that represent packages of related data and functionality. Objects are self-contained and expose specific functionality to the rest of the application environment without detailing the inner workings of the object itself. Objects are created from a template called a class. The .NET base class library provides a set of classes from which you can create objects in your applications. You also can use the Microsoft Visual Studio programming environment to create your own classes. This lesson introduces you to the conceptsObjects, Members, and Abstraction
An object is a programmatic construct that represents something. In the real world, objects are cars, bicycles, laptop, and so on. Each of these items exposes specific functionality and has specific properties. In your application, an object might be a form.Control such as a button, a database connection.or any of a number of other constructs. Each object is a complete functional unit, and contains all of the data and exposes all of the
functionality required to fulfill its purpose. The ability of
programmatic objects to represent real-world objects is called abstraction.
Classes Are Templates for Objects
Classes represent user-defined reference types. Classes can be thought of as blueprints for objects: they define all of the members of an object, define the behavior of an object, and set initial values for data when appropriate. When a class is
initialized, an in-memory instance of that class is created. This instance is called an object. To review, a class is instantiated using the New (new) keyword as follows:
Visual Basic .NET
' Declares a variable of the Widget type Dim myWidget As Widget
' Instantiates a new Widget object and assigns it to the myWidget ' variable
myWidget = New Widget()
When an instance of a class is created, a copy of the instance data defined by that class is created in memory and assigned to the reference variable. Individual instances of a class are independent of one another and represent separate
programmatic constructs.
There is generally no limit to how many copies of a single class can be initialized at any time. To use a real-world analogy, if a car is an object, plans for the car are the class. The plans can
be used to make any number of cars, and changes to a single car do not, for the most part, affect any other cars.
Objects and Members
Objects are composed of members. Members are properties, fields, methods, and events, and they represent the data and functionality that comprise the object. Fields and properties represent data members of an object. Methods are actions the object can perform, and events are notifications an object
receives from or sends to other objects when activity happens in the application.
Object Models
Simple objects might consist of only a few properties, methods, and perhaps an event or two. More complex objects might require numerous properties and methods and possibly even secondary objects. Objects can contain and expose other objects as members.
Similarly, every instance of the Form class contains and exposes a controls collection that comprises all of the controls contained by the form. The object model defines the hierarchy of contained objects that form the structure of an object.
Encapsulation
Encapsulation is the concept that implementation of an object is independent of its interface. Put another way, an application interacts with an object through its interface, which consists of its public properties and methods. As long as this interface remains constant, the application can continue to interact with the component, even if implementation of the interface was completely rewritten between versions.
Polymorphism is the ability of different classes to provide different implementations of the same public interfaces. In other words, polymorphism allows methods and properties of an object to be called without regard for the particular implementation of those members. There are two principal ways through which polymorphism can be provided: interface polymorphism and inheritance polymorphism.
Interface Polymorphism
An interface is a contract for behavior, it defines the members a class should implement, but states nothing at all about the details of that implementation. An object can implement many different interfaces, and many diverse classes can
implement the same interface. All objects implementing the same interface are capable of interacting with other objects through that interface.
Inheritance Polymorphism
Inheritance allows you to incorporate the functionality of a previously defined class into a new class and implement different members as needed. A class that inherits another class is said to derive from that class, or to inherit from that class. A class can directly inherit from only one class, which is called the base class. The new class has the same members as the base class, and additional members can be added as needed. Additionally, the implementation of base members can be changed in the new class by overriding the base class
implementation. Inherited classes retain all the characteristics of the base class and can interact with other objects as though they were instances of the base class.
Microsoft Visual Basic.Net
With its release for the .NET platform, the Visual Basic language has undergone dramatic changes. For example:
Applications and components written in Visual Basic .NET have full access to the .NET Framework, an extensive class library that provides system and application services.
All applications developed using Visual Basic .NET run within a managed runtime environment, the .NET common language runtime.
FUNCTIONS
private void generate_bincodes()
It is used to convert the string into binary codes or bit stream.This function uses the class stack to perform this task.
private void text_encrypt()
It is used to encrypt the plain text using vigenere cipher.
private string text_decrypt()
It is used to decrypt the text which is generated from the stegno medium.
private float get_key()
This function is used to manipulate the stegno key.
Public Bitmap encrypt()
This is the function responsible for hiding encryted text in the image file
public string decrypt()
System Implementation
Implementation
Implementation is the stage in the project where the theoretical design of the project is turned into a working system. It is a stage where the operation of the system is monitored to ensu re that it continues to work effectively. Education and training of the users are also essential to ensure smooth functioning of the system.
The major tasks involved in the implementation are: • Computer based/system testing.
• Training the user personnel
• Full system testing and making the necessary changes as desired by the user.
• Change over. • Maintenance.
The implementation strategy used is the parallel changeover. The automated system has been put to use gradually so that its usage can prove better for the concern.
After the system has been tested, the implementation type or the change over technique from the existing system to the new system is a step-by-step process. In the system, at first only a module of the system is implemented and checked for suitability and efficiency. When the end-user related to the particular module is satisfied with the performance, the next step of implementation is preceded.
Implementation to some extent is also parallel. For instance, modules, which are not linked, with other modules are implemented parallel and the remaining is the step-by-step process.
Backups are necessary since any time unexpected events may happen. And so during the program execution, the records are stored in the workspace. This helps to recover the original status of the
records from any accidental updating or intentional deletion of records.
Implementation Procedures
Implementation means converting older system to a new design in operation. This involves creating computer capable files and basic software needed to run this system. The basic concept for
implementation needed is software installation and system
requirements. So in order to implement them, suitable hardware and software must be available. Then the database must be created in the
computer without changing the database names which are used in the table design.
Now the computer is ready for implementing the proposed system. There are three types of implementation.
Implementation of a new computer system to replace a manual one.
Implementation of a new computer system to replace an existing one.
Implementation a modified application to replace an existing one.
User Training
Planning for user acceptance testing calls for the analyst and the user to agree on the condition for the test. Many of these conditions may be derived from the test plan. Others are an agreement on the test schedule, the test duration and the test should be specified in advance.
Plan User Training
User training is designed to prepare the user for testing and converting the system. User involvement and training take place parallel with programming for three reasons:
• The system group has time available to spend on training while the program is being written.
• Initiating a user-training program gives the system group a clears image of the user’s interest in the new system.
• A trained user participates more effectively in system testing. For user training, preparation of a checklist is useful. Included are provisions for developing training materials and other documents to complete the training activity. In effect, the checklist call for a
commitment of personnel, facilities and effort for implementing the candidate system
The training plan is followed by preparation of the user training manual and other text materials. Facility requirements and the necessary hardware are specified and documented. A common procedure is to train supervisors and heads who, in turn train their staff as they fit.
Operational Documentation
In operational document, the general idea is about explaining different module of this project. The detail explanation of this operational document is to know the form infrastructure. There are different forms that have different features, when it is selected then this displays the particular detail about the particular contents. The content will display all the details about the fields. In the particular form we can add, edit, delete and update can be made. Each form displays the particular module to perform this operation.
System Maintenance
Software maintenance is of course, redefining the system uniform. Provision must be made for environment changes, which may affect either the computer, or other parts of the computer based systems. Such activity is normally called maintenance. It includes both the improvement of the system functions and the correction of faults, which arise during the operation of a new system.
It may involve the continuing involvement of a large proportion of computer department resources. The main task may be to adapt existing systems in a changing environment. Systems should not be changed casually following informal requests. To avoid unauthorized amendments, all requests for changes should be channeled to a person nominated by management. The nominated person has
sufficient knowledge of the organization’s computer based systems to be able to judge the relevance of each proposed change.
Project Life Cycle
Data Flow Diagram for Audio Steganography
Testing is the process of executing the program with the intent of finding errors. During testing, the program to be tested and executed with a set of test cases and the output of the program for the test cases is evaluated to determine the program is
performing as it is expected. Error is the testing fundamental and is defined as the difference between the actual output of a
software and a correct output i.e., difference between the actual and ideal testing is usually relied upon to detect these faults in the coding phase for this, different levels of testing are used which performs different tasks and aim to the test different aspects of the system.
Goals of Testing:
The famous statement by Dijkstra (in Dahl et al. 1972) is a perfect synthesis of the goals of the testing. If the results
delivered by the system are different from the expected ones in just one case, in this unequally shows that the system is incorrect: by contrast, a correct behavior of the system on a finite number of cases does not guarantee correctness in the general case. For instance, we could have built a program that behaves properly for even integer numbers but not odd numbers. Clearly, any number of tests with even input values will face to show the error.
Testing should be based on sound and systematic techniques so that, after testing, we may have a better understanding of the product’s reliability.
Testing should help locate errors, not just detect their presence. The result of testing should not be viewed as simply providing a Boolean answer to the question of whether the software works properly or not.
Tests should be organized in a way that helps to isolate errors. This information can then be used in debugging.
Testing should be repeatable, i.e., tests should be arranged in such a way that separating the same experiment-supplying the same input data to the same piece of code – produces the same results.
Finally testing should be accurate – this will increase the reliability of testing. Here we should observe that the accuracy of
the testing activity depends on the level of precision and may be even formality of software specifications.
Testing Methodologies:
Unit Testing
In it different modules are tested against the specifications produced during design for the modules. It is essential for verification of the code produced during the code phase and the goal is to test the internal logic of the module.
Integration Testing
The goal here is to see if the modules can be integrated properly, the emphasis being on testing interfaces between modules. After structural testing and functional testing we get error free modules these modules are to be integrated to get the required results of the system. After checking the module another module is tested and is integrated with the previous module. After the integration the test phases are generated and the results are tested.
System Testing
Here the entire software is tested. The reference
document for this process is the requirement document and the goal is to see whether the software needs its requirements. The system was tested for various test cases with various inputs.
Validation Testing
In this testing the software is tested to determine whether it suits to that particular environment. Validation testing provides the final assurance that the software meets all functional,
behavioral and performance requirements. Validation refers to the process of using the software in a live environment to find errors. During the course of validation the system failure may occur and software will be changed.
Tested all the fields whether accepting the valid input or not.
Acceptance Testing
It is sometimes performed with realistic data of the client to demonstrate that the software is working satisfactorily. Testing here focus on the external behavior of the system, the internal logic of the program is not emphasized.
In acceptance test the system is tested for various inputs. Thus different types of testing are performed.
Black Box Testing
Here the structure of the program is not considered. Only the test cases are decided solely on the basis of the requirements or specification of the program or module and the internal details of the module or the program is not considered for the selection of test cases. This is also called “Black Box Testing” or “Functional Testing”.
Incorrect or missing functions.
Performance errors. Database access errors Initialization and termination
White Box Testing
It is considered with testing the implementation of the
program. The intention of the structural testing is not to exercise all the different input and output conditions but to exercise the different programming and data files used in the program. This testing is also called “White Box Testing” or Structural Testing.
Program.cs using System; using System.Collections.Generic; using System.Linq; using System.Windows.Forms; namespace Steganography {
staticclassProgram {
///<summary>
/// The main entry point for the application. ///</summary>
[STAThread] staticvoid Main() {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false); Application.Run(new Steganography ());
} } } Steganography.cs using System; using System.Drawing; using System.Windows.Forms; using System.Drawing.Imaging; using System.IO; namespace Steganography {
publicpartialclassSteganography : Form {
private Bitmap bmp = null;
privatestring extractedText = string.Empty; public Steganography()
{
InitializeComponent(); }
privatevoid hideButton_Click(object sender, EventArgs e) {
bmp = (Bitmap)imagePictureBox.Image; string text = dataTextBox.Text;
if (text.Equals("")) {
MessageBox.Show("The text you want to hide can't be empty",
"Warning"); return; }
if (encryptCheckBox.Checked) {
if (passwordTextBox.Text.Length < 6) {
MessageBox.Show("Please enter a password with at least 6 characters", "Warning");
return; }
else {
text = Crypto.EncryptStringAES(text, passwordTextBox.Text); }
}
bmp = SteganographyHelper.embedText(text, bmp); MessageBox.Show("Your text was hidden in the image successfully!", "Done");
notesLabel.Text = "Notes: don't forget to save your new image."; notesLabel.ForeColor = Color.OrangeRed;
}
privatevoid extractButton_Click(object sender, EventArgs e) {
bmp = (Bitmap)imagePictureBox.Image;
string extractedText = SteganographyHelper.extractText(bmp); if (encryptCheckBox.Checked) { try { extractedText = Crypto.DecryptStringAES(extractedText, passwordTextBox.Text); } catch {
MessageBox.Show("Wrong password", "Error"); return;
} }
dataTextBox.Text = extractedText; }
privatevoid imageToolStripMenuItem1_Click(object sender, EventArgs e)
{
OpenFileDialog open_dialog = new OpenFileDialog();
open_dialog.Filter = "Image Files (*.jpeg; *.png; *.bmp)|*.jpg; *.png; *.bmp"; if (open_dialog.ShowDialog() == DialogResult.OK) { imagePictureBox.Image = Image.FromFile(open_dialog.FileName); } }
privatevoid imageToolStripMenuItem_Click(object sender, EventArgs e)
{
SaveFileDialog save_dialog = new SaveFileDialog();
save_dialog.Filter = "Png Image|*.png|Bitmap Image|*.bmp"; if (save_dialog.ShowDialog() == DialogResult.OK) { switch (save_dialog.FilterIndex) { case 0: { bmp.Save(save_dialog.FileName, ImageFormat.Png); }break; case 1: { bmp.Save(save_dialog.FileName, ImageFormat.Bmp); } break; } notesLabel.Text = "Notes:"; notesLabel.ForeColor = Color.Black; } }
privatevoid textToolStripMenuItem_Click(object sender, EventArgs e)
{
SaveFileDialog save_dialog = new SaveFileDialog(); save_dialog.Filter = "Text Files|*.txt";
if (save_dialog.ShowDialog() == DialogResult.OK) {
File.WriteAllText(save_dialog.FileName, dataTextBox.Text); }
}
privatevoid textToolStripMenuItem1_Click(object sender, EventArgs e)
{
OpenFileDialog open_dialog = new OpenFileDialog(); open_dialog.Filter = "Text Files|*.txt";
if (open_dialog.ShowDialog() == DialogResult.OK) {
dataTextBox.Text = File.ReadAllText(open_dialog.FileName); }
}
privatevoid aboutToolStripMenuItem_Click(object sender, EventArgs e)
{
MessageBox.Show("By: Shrikant Pokharkar @ April 2015",
"About"); }
privatevoid notesLabel_Click(object sender, EventArgs e) {
privatevoid groupBox2_Enter(object sender, EventArgs e) {
}
privatevoid groupBox3_Enter(object sender, EventArgs e) { } } } Steganography.Designer.cs namespace Steganography {
partialclassSteganography {
///<summary>
/// Required designer variable. ///</summary>
private System.ComponentModel.IContainer components = null; ///<summary>
/// Clean up any resources being used. ///</summary>
///<param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protectedoverridevoid Dispose(bool disposing) {
if (disposing && (components != null)) {
components.Dispose(); }
base.Dispose(disposing); }
#region Windows Form Designer generated code ///<summary>
/// Required method for Designer support - do not modify /// the contents of this method with the code editor. ///</summary>
privatevoid InitializeComponent() {
this.hideButton = new System.Windows.Forms.Button(); this.dataTextBox = new System.Windows.Forms.TextBox(); this.extractButton = new System.Windows.Forms.Button(); this.menuStrip1 = new System.Windows.Forms.MenuStrip(); this.fileToolStripMenuItem = new
System.Windows.Forms.ToolStripMenuItem(); this.openToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem(); this.imageToolStripMenuItem1 = new System.Windows.Forms.ToolStripMenuItem(); this.textToolStripMenuItem1 = new System.Windows.Forms.ToolStripMenuItem();
