STEGANOGRAPHY A PROJECT REPORT SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF BACHELOR OF TECHNOLOGY in INFORMATION TECHNOLOGY TO
Gautam Buddh Technical University
SUBMITTED BY Rakhi Rani(0806813040) Shikha Yadav(0806813047) Sachin Choudhary(0806813043) Mridu Kakran(0806813030)
DEPARTMENT OF INFORMATION TECHNOLOGY MEERUT INSTITUTE OF ENGINEERING & TECHNOLOGY, BYPASS ROAD, MEERUT-250005, INDIA MAY, 2012
CERTIFICATE
This is to certify that this thesis report titled, “ STEGANOGRAPHY ”, submitted by Rakhi STEGANOGRAPHY”, Rani, Shikha Yadav, adav, Sachin Choudhary, Mridul Kakran in partial fulfillment of the requirement for the award of Bachelor of Technology (Information Technology) degree, Gautam Buddh Technical University, Lucknow, India is a record of student’s own study carried under my supervision and guidance.
The pre-thesis report has not been submitted to any other university or institution for the award of any degree.
Guide
Prof. Ramendra Singh designation:-Lecturer department:-IT MIET, Meerut
CERTIFICATE
This is to certify that this thesis report titled, “ STEGANOGRAPHY ”, submitted by Rakhi STEGANOGRAPHY”, Rani, Shikha Yadav, adav, Sachin Choudhary, Mridul Kakran in partial fulfillment of the requirement for the award of Bachelor of Technology (Information Technology) degree, Gautam Buddh Technical University, Lucknow, India is a record of student’s own study carried under my supervision and guidance.
The pre-thesis report has not been submitted to any other university or institution for the award of any degree.
Guide
Prof. Ramendra Singh designation:-Lecturer department:-IT MIET, Meerut
ACKNOWLEDGEMENT First of all, I would like to thank God for everything. I also would like to thank all the people who helped me during this work.
I would like to express my deepest gratitude to my supervisorsfor their invaluable suggestions and guidance, constant encouragement and patience during the course of this work.
I would like to thank to the Director, MIET for providing a rich intellectual environment, and facilities facilities indispensable indispensable for the writing of this pre-thesis. pre-thesis. Special Special thanks to Prof. Abhilash Abhilash Sharma for his constant encouragement and support throughout the course work.
I would also like to acknowledge the support of Meerut Institute of Engineering & Technology (MIET), Meerut. Meerut. U.P., U.P., throughout my studies and the support of all the MIET staff. staff. Part of this pre thesis work was done on the Workstations in the laboratory established under grant MODROBS by AICTE through letter no. 8024/RID/BOR/MOD-863/2009-10.
Lastly Lastly, and most importantly, importantly, I wish to thank my parents. parents. Without Without their love and support, support, nothing would have been possible.
....................
Rakhi Rani(0806813040) Shikha Yadav(0806813047) Sachin Choudhary(0806813043) Mridul Kakran(0806813030) Kakran(0806813030)
ABSTRACT The Internet as a whole does not use secure links, thus information in transit may be vulnerable to interception as well. The importance of reducing a chance of the information being detected during the transmission is being an issue now days. Some solution to be discussed is how to pass information in a manner that the very existence of the message is unknown in order to repel attention of the potential attacker. Besides hiding data for confidentiality, this approach of information hiding can be extended to copyright protection for digital media. In this research, we clarify what steganography is, the definition, the importance as well as the technique used in implementing steganography. We focus on the Least Significant Bit (LSB) technique in hiding messages in an image.
The system enhanced the LSB technique by randomly dispersing the bits of the message in the image and thus making it harder for unauthorized people to extract the original message.
List of Figures 4.1
Data Flow Diagram Level-0
. . . . . . . . . . . . . . . . . . . . . . . . . . .
16
4.2
Flow of Data within project . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18
4.3
Use Case Diagram
20
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iv
Contents
1
2
INTRODUCTION
1
1.1
What is Steganography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
1.2
Needs And Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
1.3
Steganography Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
1.4
Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
1.5
Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
1.6
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
LITERATURE SURVEY
6
2.1
Approaches of Image Steganography . . . . . . . . . . . . . . . . . . . . . . .
6
2.2
Brief History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
2.2.1
. . . . . . . . . . . . . . . . . . . . . . . . . . .
7
Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
2.3.1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
2.3.2
Planing Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
2.3.3
Gantt Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
2.3.4
PERT chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
2.3
3
LSB Steganography
PROBLEM STATEMENT AND METHODOLOGY
12
3.1
Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
3.2
Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12
3.2.1
Symmetric Encryption . . . . . . . . . . . . . . . . . . . . . . . . . .
12
3.2.2
Asymmetric Key Encryption . . . . . . . . . . . . . . . . . . . . . . .
13
v
3.2.3 4
5
6
DES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
SYSTEM DESIGN
15
4.1
Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
4.2
Project Development Approach . . . . . . . . . . . . . . . . . . . . . . . . . .
15
4.2.1
Data Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
4.2.2
Flow Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17
4.2.3
Use Case Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
PERFORMANCE AND WORK DONE
21
5.1
Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
5.1.1
Evaluation Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
5.1.2
Work Done . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23
CONCLUSION AND FUTURE WORK
24
6.1
CONCLUSION AND FUTURE WORK . . . . . . . . . . . . . . . . . . . . .
24
6.1.1
Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24
6.1.2
Future Work
25
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
References
26
vi
Chapter 1
INTRODUCTION 1.1
What is Steganography
Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. The word steganography is of Greek origin and means "concealed writing" from the Greek words steganos meaning "covered or protected", and graphei meaning "writing". The first recorded use of the term was in 1499 by Johannes Trithemius in his Steganographia, a treatise on cryptography and steganography disguised as a book on magic. Generally, messages will appear to be something else: images, articles, shopping lists, or some other covertext and, classically, the hidden message may be in invisible ink between the visible lines of a private letter.
The advantage of steganography, over cryptography alone, is that messages do not attract attention to themselves. Plainly visible encrypted messagesno matter how unbreakablewill arouse suspicion, and may in themselves be incriminating in countries where encryption is illegal Therefore, whereas cryptography protects the contents of a message, steganography can be said to protect both messages and communicating parties.
Steganography includes the concealment of information within computer files. In digital
1
steganography, electronic communications may include steganographic coding inside of a transport layer, such as a document file, image file, program or protocol. Media files are ideal for steganographic transmission because of their large size. As a simple example, a sender might start with an innocuous image file and adjust the color of every 100th pixel to correspond to a letter in the alphabet, a change so subtle that someone not specifically looking for it is unlikely to notice it.
1.2
Needs And Application
The advantage of steganography, over cryptography alone, is that messages do not attract attention to themselves. Plainly visible encrypted messagesno matter how unbreakablewill arouse suspicion, and may in themselves be incriminating in countries where encryption is illegal. Therefore, whereas cryptography protects the contents of a message, steganography can be said to protect both messages and communicating parties. Steganography includes the concealment of information within computer files. In digital steganography, electronic communications may include steganographic coding inside of a transport layer, such as a document file, image file, program or protocol. Media files are ideal for steganographic transmission because of their large size. As a simple example, a sender might start with an innocuous image file and adjust the color of every 100th pixel to correspond to a letter in the alphabet, a change so subtle that someone not specifically looking for it is unlikely to notice it.
Steganography is applicable to, but not limited to, the following areas.
•
Confidential communication and secret data storing
•
Protection of data alteration
•
Access control system for digital content distribution
•
Media Database systems
2
1.3
Steganography Concepts
The modern formulation of steganography is often given in terms of the prisoner’s problem where Alice and Bob are two inmates who wish to communicate in order to hatch an escape plan. However, all communication between them is examined by the warden, Wendy, who will put them in solitary contnement at the slightest suspicion of covert communication. Specifically, in the general model for steganography, we have Alice wishing to send a secret message m to Bob. In order to do so, she "embeds" m into a cover-object c, and obtains a stego-object s. The stego-object s is then sent through the public channel. Thus we have the following defnitions:
Cover-object:
refers to the object used as the carrier to embed messages into. Many different
objects have been employed to embed messages into for example images, audio, and video as well as structures, and html pages to name a few.
Stego-object:
refers to the object which is carrying a hidden message. so given a cover object,
and a messages the goal of the steganographer is to produce a stego object which would carry the message.
In a pure steganography framework, the technique for embedding the message is unknown to Wendy and shared as a secret between Alice and Bob. However, it is generally considered that the algorithm in use is not secret but only the key used by the algorithm is kept as a secret between the two parties, this assumption is also known as Kerchoff’s principle in the field of cryptography. The secret key for ex: ,can be a password used to seed a pseudo random number generater to select pixel locations in an image cover object for embedding the secret message.
An algorithm is used to disperse the hidden message throughout the file •
Common hiding techniques
•
Appended to a file
•
Modification of LSB (Least Significant Bit)
3
1.4
Motivation
The primary reason for selecting steganography among the list ofpossible project topics was due to the unfamiliarity of the word that twigged an interest in the subject.Another motivation for researching the topic was after reading an online article in the USA Today titled "Terror groups hide behind Web encryption" that claims terrorists and, in particular, Osama bin Laden and the al-Qaida network, may be using steganography to communicate with each other in planning terrorist attacks. It is thought that images with hidden messages are placed on bulletin boards or dead drops for other terrorists to pick up and retrieve hidden messages. Thus far, this supposition has yet to be proven.
1.5
Objective
The goal of steganography is hide the fact that communication is taking place. 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 goal 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
•
To extract techniques of getting secret data using decryption module.
•
Providing Security.
1.6
Scope
The scope of the project is as follow:-
4
•
Implementation of steganographic tools for hiding information includes text and image files.
•
Three different approaches being explore which are least significant bit, masking and filtering algorithms and transformation
5
Chapter 2
LITERATURE SURVEY 2.1
Approaches of Image Steganography
Information hiding generally relates with watermarking and steganography. Three aspect of information hiding must be meeting to satisfy the information hiding prospectus. The three aspects are: security, robust and capacity (Provos. Honeyman , 2003). Security is a way which the steganography medium is fully unsuspicious to eavesdroppers. Robust can be defined as the amount of modification that the steganography medium can withstand before the hidden message revealed. Amount of cover medium must meet the size of hidden data so as not to arouse eavesdropper’s suspicion.
There are two major reasons why people want to hide information (Ismail, 2003). The first reason is to protect their intellectual property rights. This kind of steganography is called watermarking. Watermarking has its own rules of thumb which it should beimpossible to remove watermark without degrading it. Its primary goal is to achieve the highest level of robustness. By implementing digital watermarking, intellectual property rights can be protected and it could be used to enforce copyright laws (Bret, 2002).
Another reason of using steganography is to hide information, especially when a user intends to send the information through the open system, unnoticed by any unintended party. It conveys information, especially confidential information, in a covert manner. In this way, only the in-
6
tended parties recognize the existence of their communication. Steganography is taken world attention after spread rumors about Osama Laden and its Al-Qaeda organization communicating with each other using steganography technique.
2.2
Brief History
Another story is about a soldier needed to send a secret message to Sparta. The soldier, Demeratus needed to warn about Xerxes’s intension to invade Greece. The secret message was written on wax-covered tablets (Joshua, 2001). Demeratus wrote the secret message on the underlying wood after removing the wax, and then covered it back with wax. The tablets seem like blank tablets and the secret information was sent without being detected. (Provos Honeyman, 2001). Romans used natural substances like fruit juic es and milks as their invisible inks. The ink will then be heated to reveal its contents nowadays,invisible inks are still being used (Syahren, 2004). Steganography word is originated form two Greek words. Steganos means secret graphy means writing (Syahren,2004). The combination of this two Greek words hold steganographic system environment, hidden message. The purpose of steganography is to hide secret information into cover medium (Provos Honeyman, 2001). Around 440 BC, a Greek Histrian, Herodotus wrote in his chronicles, History, about two incidents related to steganography (Syahren, 2004). The first stated that King Darius of Susa wrote a secret message on one of his prisoner’s shaved head. Then after prisoner’s hair grew back, he was sent to Aristogoras in Miletus, the King son-in-law, carrying the secret message undetected (Syahren, 2004).
2.2.1
LSB Steganography
As mentioned before, many types of timetabling problems exist. But all these problems have several properties in common. One of these similarities is that certain entities have to be scheduled. For example, the high school timetabling problem has several entities such as classes or students, teachers, subjects, lessons and rooms. All these entities have properties. For example classes are linked to the subject the students of this class are taught.
7
Usually, these entities are differentiated into resources and events (or sometimes called meetings). In addition, constraints have to be considered. In the employee timetabling case, for instance, we find those entities, too. There are employees with different qualifications and monthly target hours or there are shifts to be assigned to employees. As already mentioned, some of these entities are linked with others. There exist links from the shifts to the employees assigned to these shifts or from the classes to their teachers. Some of these links are fixed, such as the links from the shifts to the employees with the qualifications required to work on these shifts, and cannot be changed. Others have to be assigned during a planning process, e.g. linking a lesson to a suitable room. A planning algorithm has to construct a timetable, so we have to define what a timetable consists of. A timetable can be interpreted as an arbitrary sequence of events. To every event a certain number of time intervals are assigned, each having a starting and an ending point.
2.3 2.3.1
Planning Purpose
The purpose of Software Project Planning is to establish reasonable plans for performing the software engineering and for managing the software project. Software Project Planning involves developing estimates for the work to be performed, establishing the necessary commitments, and defining the plan to perform the work.
2.3.2
Planing Phase
The software planning begins with a statement of the work to be performed and other constraints and goals that define and bound the software project (those established by the practices of the Requirements Management key process area). The software planning process includes steps to estimate the size of the software work products and the resources needed, produce a schedule, identify and assess software risks, Iterating through these steps may be necessary to establish the plan for the software project (i.e., the software development plan).
8
2.3.3
Gantt Chart
A Gantt chart can be developed for the entire project. It depicts a part of a software project schedule that emphasizes the concept scooping task for a new software project. All project tasks (for concept scooping) are listed in the left hand column. The horizontal bars show the time needed to complete an activity. A Gantt chart is a graphical representation of the duration of tasks against the progression of time. It is a useful tool for planning and scheduling projects. It is helpful when monitoring a project’s progress. A Gantt chart is a type of bar chart that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. Some Gantt charts also show the dependency relationships between activities. Although a Gantt chart is useful and valuable for small projects that fit on a single sheet or screen, they can become quite unwieldy for projects with more than about 30 activities. Larger Gantt charts may not be suitable for most computer displays. A related criticism is that Gantt charts communicate relatively little information per unit area of display. That is, projects are often considerably more complex than can be communicated effectively with a Gantt chart. Gantt charts only represent part of the triple constraints of projects, because they focus primarily on schedule management. Moreover, Gantt charts do not represent the size of a project or the relative size of work elements, therefore the magnitude of a behind-schedule condition is miss communicated. If two projects are the same number of days behind schedule, the larger project has a larger impact on resource utilization, yet the Gantt does not represent this difference.
9
year project/final report/Steganography Report/Gantt Chart.png
2.3.4
PERT chart
Complex projects require a series of activities, some of which must be performed sequentially and others that can be performed in parallel with other activities. This collection of series and parallel tasks can be modeled as a network. The Program Evaluation and Review Technique (PERT) is a network model that allows for randomness in activity completion times. PERT was developed in the late 1950’s for the U.S.
10
Navy’s Polaris project having thousands of contractors. It has the potential to reduce both the time and cost required to complete a project. PERT is a method to analyze the tasks involved in completing a given project, especially the time needed to complete each task, and identifying the minimum time needed to complete total project.
•
A PERT event: is a point that marks the start or completion of one or more tasks. It consumes no time and uses no resources. It marks the completion of one or more tasks, and is not "reached" until all of the activities leading to that event have been completed.
•
A predecessor event: an event (or events) that immediately precedes some other event without any other events intervening. It may be the consequence of more than one activity.
•
A successor event: an event (or events) that immediately follows some other event without any other events intervening. It may be the consequence of more than one activity.
•
A PERT activity: is the actual performance of a task. It consumes time, it requires resources (such as labor, materials, space, machinery) and it can be understood as representing the time, effort, and resources required to move from one event to another. A PERT activity cannot be completed until the event preceding it has occurred.
•
Optimistic time (O): the minimum possible time required to accomplish a task, assuming everything proceeds better than is normally expected
•
Pessimistic time (P): the maximum possible time required to accomplish a task, assuming everything goes wrong (but excluding major catastrophes).
•
Most likely time (M): the best estimate of the time required to accomplish a task, assuming everything proceeds as normal.
•
Expected time (TE): the best estimate of the time required to accomplish a task, assuming everything proceeds as normal (the implication being that the expected time is the average time the task would require if the task were repeated on a number of occasions over an extended period of time).
11
Steps in the PERT Planning Process •
Identify the specific activities and milestones.
•
Determine the proper sequence of the activities.
•
Construct a network diagram.
•
Estimate the time required for each activity.
•
Determine the critical path.
Update the PERT chart as the project progresses.
12
year project/final report/Steganography Report/PERT Chart.png
13
Chapter 3
PROBLEM STATEMENT AND METHODOLOGY In this chapter we first explain the problem statement. Then we are discussing the methodology for solving the problem.
3.1
Problem Statement
The Internet as a whole does not use secure links, thus information in transit may be vulnerable to interception as well. The importance of reducing a chance of the information being detected during the transmission is being an issue now days. Some solution to be discussed is how to pass information in a manner that the very existence of the message is unknown in order to repel attention of the potential attacker.
3.2
Methodology
Two methodologies can be adopted-
3.2.1
Symmetric Encryption
It is a technique in which a single key is used for encryption decryption.In this we encrypt plain text with the help of symmetric key to form cipher text send to the destination where it is decrypted using the same symmetric key.
14
year project/final report/Steganography Report/Symmetric key Encryption.png
3.2.2
Asymmetric Key Encryption
In asymmetric encryption, also known as public key encryption or public key cryptography:
•
the key used to encrypt messages is different to the key used to decrypt those messages;
•
the key used for encryption is called the public key, and can be distributed freely;
•
the key used for decryption is called the private key, and must be kept a secret among parties that are allowed to decrypt messages encrypted with the public key;
•
the public and private keys form a key pair: they are generated togther and generally have some mathematical relationship between one another, so that to decrypt a message encrypted with a given public key, the decrypting party must know the private key that forms the "other half of the pair";
15
year project/final report/Steganography Report/Asymmetric key Encryption.png
3.2.3
DES
This algorithm is used for encryption and decryption of the hidden data. The public key can be known to everyone and is used for encrypting messages. Messages encrypted with the public key can only be decrypted using the private key. It secure from brute-force-attack.
16
Chapter 4
SYSTEM DESIGN 4.1
Purpose
The purpose of design document is to build the project in a manner specified and developed the project in such a way that it is able to satisfy the user requirement and develop according the requirement of user.
4.2
Project Development Approach
The development of this project has been performed in a systematic manner, adopting the systems Approach. UML diagrams have been used that provide a better insight to the user requirements.
4.2.1
Data Flow Diagram
DFD is a graphical representation technique for showing functions as well as data flow within the system. It is used for modeling requirements.
17
Figure 4.1: Data Flow Diagram Level-0
18
4.2.2
Flow Chart
A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. This diagrammatic representation can give a step-by-step solution to a given problem. Process operations are represented in these boxes, and arrows connecting them represent flow of control. Data flows are not typically represented in a flowchart, in contrast with data flow diagrams; rather, they are implied by the sequencing of operations.
19
Figure 4.2: Flow of Data within project
20
4.2.3
Use Case Diagram
Use case diagrams model the functionality of system using actors and use cases. Use case diagram visually represents what happens when an actor interacts with a system. This approach uses a combination of text and pictures in order to improve the understanding of requirements. The use case describes what of a system and not how. They only give functional view of the system.
Terms used:
Actor:
Actor is an external agent that lies outside the system model but interacts with it
in some or the other way. An actor may be a person, machine or an information system that is external to the system model. An actor is represented by a stick figure and is not a part of the system itself. Customers, users, external devices interacting with the system are treated as actors.
Use cases:
It is initiated by the user with a particular goal in mind, and completes success-
fully when that goal is satisfied. it describes the sequence of interactions between actors and the system necessary to deliver the services that satisfies the goal. It also includes possible variants of this sequence. The system is represented by the rectangular box that contains oval shaped use cases. The actors are represented by the sticks as shown in figure above. The use case can be described as: Figure 4.4 shows the Use Case Diagram.
21
22
Figure 4.3: Use Case Diagram
Chapter 5
PERFORMANCE AND WORK DONE 5.1
Performance
In order to reasonably evaluate the performance of various kinds of steganographic and steganalytic methods, it is necessary to de ne some criteria acceptable to the majority. Moreover, the evaluation criteria may also lead us to the right direction to improve the techniques.
5.1.1
Evaluation Criteria
.
Criteria for Steganography
. Three common requirements, security, capacity, and imper-
ceptibility, may be used to rate the performance of steganographic techniques.
Security
Steganography may su er from many active or passive attacks, correspond-ingly
in the prisoner’s problem when Wendy acts as an active or passive warden. If the existence of the secret message can only be estimated with a probability not higher than random guessing in the presence of some steganalytic systems, steganography may be considered secure under such steganalytic systems. Otherwise we may claim it to be insecure.
23
Capacity.
To be useful in conveying secret message, the hiding capacity provided by
steganography should be as high as possible, which may be given in absolute measurement (such as the size of secret message), or in relative value (called data embedding rate, such as bits per pixel, bits per non-zero discrete cosine transform coe cient, or the ratio of the secret message to the cover medium, etc.).
Imperceptibility.
Stego images should not have severe visual artifacts. Under the same
level of security and capacity, the higher the delity of the stego image, the better. If the resultant stego image appears innocuous enough, one can believe this requirement to be satis ed well for the warden not having the original cover image to compare
Criteria for Steganalysis.
The main goal of steganalysis is to identify whether or not a sus-
pected medium is embedded with secret data, in other words, to determine the testing medium belong to the cover class or the stego class. If a certain steganalytic method is used to steganalyze a suspicious medium, there are four possible resultant situations.
True positive (TP), meaning that a stego medium is correctly classi ed as stego. False negative (FN), meaning that a stego medium is wrongly classi ed as cover. True negative (TN), meaning that a cover medium is correctly classi ed as cover. False positive (FP), meaning that a cover medium is wrongly classi ed as stego.
improving Steganographic Security
Increasing the embeding efficiency
Reducing the embeding distortion
24
5.1.2
Work Done
Following tasks have been completed till now:•
Watermarking and data hiding techniques for binary document images can be classified according to one of the following embedding methods: text line, word, or character shifting, boundary modifications, fixed partitioning of the image into blocks, modification of character features, modification of run-length patterns, or modifications of half-tone images. In the rest of this section we describe representative techniques for each of these methods.
•
Quantitative methods should also be developed to evaluate the quality of marked images. The steganographic capability of different techniques needs to be investigated and techniques that can be used in covert communication applications need to be developed.
•
The larger the cover message is (in data content termsnumber of bits) relative to the hidden message, the easier it is to hide the latter.
25
Chapter 6
CONCLUSION AND FUTURE WORK 6.1 6.1.1
CONCLUSION AND FUTURE WORK Conclusion
The proposed approach in this project uses a new steganographic approach called image steganography. The application creates a stego image in which the personal data is embedded and is protected with a password which is highly secured. The main intention of the project is to develop a steganographic application that provides good security. The proposed approach provides higher security and can protect the message from stego attacks. The image resolution doesn’t change much and is negligible when we embed the message into the image and the image is protected with the personal password. So, it is not possible to damage the data by unauthorized personnel. We used the Least Significant Bit algorithm in this project for developing the application which is faster and reliable and compression ratio is moderate compared to other algorithms. the compression depends on the document size as well as the carrier image size.
Steganography has its place in security. It is not intended to replace cryptography but supplement it. Hiding a message with steganography methods reduces the chance of a message being
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detected. However, if that message is also encrypted, if discovered, it must also be cracked (yet another layer of protection).
6.1.2
Future Work
The future work on this project is to improve the compression ratio of the image to the text. The security using Least Significant Bit Algorithm is good but we can improve the level to a certain extent by varying the carriers as well as using different keys for encryption and decryption. The scope of the project is to limit unauthorized access and provide better security during message transmission.
This work of mine is one of the most candid extracts from the witch of ’JAVA’. I am very optimistic about the future prospects of this project. Electronic Data Interchange will be a problem of lifetime for IT field so this project is just a small module of that big area of Steganography, as the time passes and according to the need generate new algorithms will be developed and so future of the Steganography is safe.
As far as I can see Steganography is the future of this kind of a project, so the scope of the project will never going to end.
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