Technique to Hide Information Within Image Files Using LSB (Least Significant Bit)

Now a day the sharing of images over network is increasing in large numbers. The network security is becoming more important as the number of data being exchanged on the internet increases. More over the data that is relevant for the image is also send along with it. Therefore, the confidentiality and data integrity requires protecting against unauthorized access and use. This has resulted in an explosive growth of the field of information hiding. Data hiding is a technique that is used to hide information in digital media such as images, video, audio etc. This technique is also referred to as steganography. Here the data is hidden in the image. The data may be the information about the image itself. The data hidden must be recoverable. Since in most of the application hiding of data in the image and the reversible process is essential. Reversible data hiding was first proposed for authentication and its important feature is reversibility, it hide the secret data in the digital image in such a way that only the authorized person could decrypt the secret information and restore the original image. Several data hiding methods have been proposed. 

The performance of a reversible data embedding algorithm is measured by its payload capacity, complexity, visual quality and security. Earlier methods have lower embedding capacity and poor image quality. As the embedding capacity and image quality is improved, this method became a convert communication channel. Not only the data hiding algorithm be given importance but also the image on which the data is hidden should also be highly secured. This security is provided in two layers. First the data that is to be hidden in the image is encrypted using AES algorithm. This encrypted data is then hidden in the image. The image with the hidden data is then encrypted again. Thus the user with the decryption key of both image and data will be able to retrieve the data and image in its original form. Data hiding is a process of retrieving the useful knowledge from the large data/datasets. This definition looks very simple and short but has a very deep meaning in that. It actually means that a good amount of data has been given to you and you have been given a task to hide it out only that information that is useful to you and can further help us in our future works. Recognising the rare and unknown patterns from the large amount of data is a very crucial process classifying the data and separating out only the useful one.[1] Data hiding is”rapidly growing successful in a wide range of applications . Data hiding is an emerging field of high importance for providing secure transmission.

The fast growth of the electronic era has led to all documentations, audio and video being digitized. This has increased the requirement for ensuring the safety and reliability of any document, audio and video to maintain privacy, and to prevent piracy and mass reproduction. This requirement varies from an individual to individual. The techniques used for ensuring this are cryptography and steganography of which the former is perceptible as noise while the latter is imperceptible to the human eye.Current Digital multimedia providesrobust and easy ways of editing data. This data needs to be delivered safely over computer networks without interference. Steganography is a method that hides data among the bits of a cover file like a graphic or an audio file. The word Steganography is Greek in origin and implies covered writing or hiding from plain sight (Cachin 1998). Steganography’searliest usage is documented in History (Herodotus 1992), around 440 B.C. American Revolution saw the usage of invisible ink which could glow in heat, used by the British and Americans for secret communication (Caldwell 2003). In world war two, German spies used invisible dots in letters and changed heights of letter-strokes to hide messages

Steganography become more important as more people join the cyberspace revolution.  Steganography is the art of concealing information in ways that prevents the detection of hidden messages.

Steganography is distinct from cryptography, but using both together can help improve the security of the protected information and prevent detection of the secret communication. If steganographically-hidden data is also encrypted, the data may still be safe from detection -- though the channel will no longer be safe from detection. There are advantages to using steganography combined with encryption over encryption-only communication.

The primary advantage of using steganography to hide data over encryption is that it helps obscure the fact that there is sensitive data hidden in the file or other content carrying the hidden text. Whereas an encrypted file, message or network packet payload is clearly marked and identifiable as such, using steganographic techniques helps to obscure the presence of the secure channel.

 

Steganography software is used to perform a variety of functions in order to hide data, including encoding the data in order to prepare it to be hidden inside another file, keeping track of which bits of the cover text file contain hidden data, encrypting the data to be hidden and extracting hidden data by its intended recipient. There are proprietary as well as open source and other free-to-use programs available for doing steganography. Open Stego is an open source steganography program; other programs can be characterized by the types of data that can be hidden as well as what types of files that data can be hidden inside. Some online steganography software tools include Xiao Steganography, used to hide secret files in BMP images or WAV files; Image Steganography, a Javascript tool that hides images inside other image files; and Crypture, a command line tool that is used to perform steganography. Steganography can be used to conceal almost any type of digital content, including text, image, video or audio content; the data to be hidden can be hidden inside almost any other type of digital content. The content to be concealed through steganography -- called hidden text -- is often encrypted before being incorporated into the innocuous-seeming cover text file or data stream. If not encrypted, the hidden text is commonly processed in some way in order to increase the difficulty of detecting the secret content.

Steganography is practiced by those wishing to convey a secret message or code. While there are many legitimate uses for steganography, malware developers have also been found to use steganography to obscure the transmission of malicious code.

The late development in computational force and innovation has pushed the requirement for exceptionally secured information correspondence. One of the best strategies for secure correspondence is Steganography-an undercover composition. It is a specialty of concealing the very presence of imparted message itself. The methodology of utilizing steganography as a part of conjunction with cryptography, called as Dual Steganography, builds up a strong model which includes a great deal of difficulties in recognizing any concealed and scrambled information. Utilizing cryptographic systems to scramble information before transmission may prevent any sort of security issues. Be that as it may the disguised appearance of scrambled information may stimulate suspicion.

Along these lines utilizing steganography inside steganography, offer climb to enhanced form of double steganography which will give better security. This paper exhibits a procedure for concealing information with two level of security to install information alongside great perceptual straightforwardness and high payload limit. Steganography is the investigation of undetectable correspondence which shrouds any private information inside a blameless looking spread item. The statement Steganography is gotten from the Greek words "stegos" signifying "spread" and "grafia" signifying "composition" characterizing it as "secured written work" .Steganography is not quite the same as cryptography. The objective of cryptography is to give secure interchanges by changing the information into a structure that can't be caught on. Steganography procedures, then again, conceal the presence of the message itself, which makes it awkward for a third individual to figure out the message.

Not at all like steganography, sending scrambled data may draw consideration. Steganography today, then again, is altogether more complex, permitting a client to conceal a lot of data inside picture and sound documents. These types of steganography regularly are utilized as a part of conjunction with cryptography so that the data is doubly secured; first it is encoded and afterward shrouded so that an enemy needs to first find the data (a frequently troublesome assignment all by itself) and afterward decode it. Appropriately, cryptography is not the great answer for secure correspondence yet just piece of the arrangement. Both procedures can be utilized together to better ensure data . The model comprises of Carrier (C), Secret Data (D), and Stego Key (K). Transporter is the spread question in which the mystery message is implanted. Mystery information can be any sort of secret information i.e. plain content, figure content or other picture. Key primarily used to guarantee that just beneficiary having the interpreting key will have the capacity to recover the mystery message from the spread article. With the assistance of installing calculation, the mystery information is inserted into the spread question in a manner that does not change the first picture in a human noticeable manner. At long last, the stego object which is the yield of the methodology is only the spread article with installed mystery information. The exploration of securing an information by encryption is Cryptography though the strategy for concealing mystery messages in different messages is Steganography, so that the mystery's extremely presence is covered.

The term "Steganography" depicts the system for concealing cognitive substance in an alternate medium to keep away from location by the interlopers. This paper presents two new strategies wherein cryptography and steganography are consolidated to scramble the information and in addition to shroud the scrambled information in an alternate medium so the way that a message being sent is hidden. One of the systems demonstrates to secure the picture by changing over it into figure message by S-DES calculation utilizing a mystery key and hide this content in an alternate picture by steganographic system. An alternate strategy demonstrates another method for concealing a picture in an alternate picture by encoding the picture straightforwardly by S-DES calculation utilizing a key picture and the information got is hidden in an alternate picture. The proposed technique keeps the potential outcomes of steganalysis too. [6] Shilpa Gupta, Geeta Gujral and Neha Aggarwal developed an enhanced LSB algorithm which embeds the secret data only in one i.e. blue component instead of all RGB components.

With this new technique, the performance of LSB has been improved which leads to the minimization of the distortion level that is negligent to human eye. This will increase the robustness but will decrease the payload capacity. [7]Shailender Gupta, Ankur Goyal and Bharat Bhushan developed a technique for hiding data using LSB steganography and cryptography where the secret information is encrypted using RSA or Diffie Hellman algorithm before embedding in the image with the help of LSB method. With the proposed technique, time complexity is increased but high security is achieved at that cost. Tanmay Bhattacharya, Nilanjan Dey and S. R. Bhadra Chaudhuri proposed a DWT based Dual steganographic technique. By using DWT, a cover image is decomposed into four subbands. Two secret images are hidden within HL and HH subbands respectively by usage of a pseudo random sequence and a session key. By this technique fair amount of information is transferred in a secured way with an acceptable level of imperceptibility. [8] K.Sakthisudhan and P.Prabhu proposed a dual steganography approach in which the secret data is firstly converted to encrypted form and then LSB technique of steganography is used to embed it within cover object. By this method, message is transferred with utmost security and can be retrieved without any loss of data.

[9] Rosziati Ibrahim and Teoh Suk Kuan developed a SIS (Steganography Imaging System) in which two layers of security are used, firstly username and password are required and once login done, key is used to embed the secret data. Due to this, integrity and privacy is maintained. The objective of this examination work is to investigate double steganography and its applications in secure, continuous way. Steganography is the procedure of concealing a mystery message inside a bigger one such that the vicinity of the mystery message can't be distinguished. For this situation, client verification data will be installed in crude sound information in a system.

This can be fulfilled by utilizing the slightest critical bit of a LSB test to store one bit of an encoded message. With a fitting decoder, the mystery message can be separated from an alternate LSB test while the ordinary client would have no clue that it exists. In the proposed plan, double picture steganography is utilized. The purpose for utilizing picture steganography is that pictures are more prominent among the web clients. In this work, 4 bit LSB substitution method falling under the class of spatial space is utilized by which high security is attained to for mystery information alongside great measure of impalpability and additionally high payload limit.

The algorithm works as follows: 1) Cover image1 is separated into RGB planes. 2) Secret data taken is then converted into binary form. 3) Those values are separated into upper and lower nibbles which are embedded in two separate planes of the cover image1. 4) Upper nibbles are embedded in green plane and lower nibbles in red plane. 5) Stego key is embedded inside the blue plane. 6) After which, all the three planes are combined to generate stego image1. 7) Stego image1 is then interpreted as secret data and embedded in the cover image2 using the same algorithm and thus the final stego image is generated. In data extraction process we using the final stego image, the stego image1 is extracted using stego key1 and LSB recovery algorithm. Next, from stego image1, secret data is extracted by using stego key2 and same LSB recovery algorithm. The proposed scheme is irreversible one as the cover image is not recovered at the receiver side. The algorithm works as follows: 1) Final stego image is separated into RGB planes. 2) Stego key which acts as password is entered whichis then verified with the stored key that is embedded in the blue plane of cover image2. 3) If the key is matched then the upper and lower nibbles of binary secret data is extracted from green and red planes respectively. 4) Then the upper and lower nibbles are combined to make the binary form of stego image1. 5) Finally, the original stego image1 is obtained from binary form. 6) Next, using the same algorithm the original secret data is retrieved from stego image

Stegranography include an array of secret communication methods that hide the message from being seen or discovered.

Due to advances in ICT, most of information is kept electronically. Consequently, the security of information has become a fundamental issue. Besides cryptography, streganography can be employed to secure information. In cryptography, the message or encrypted message is embedded in a digital host before passing it through the network, thus the existence of the message is unknown. Besides hiding data for confidentiality, this approach of information hiding can be extended to copyright protection for digital media: audio, video and images.

The growing possibilities of modern communications need the special means of security especially on computer network. The network security is becoming more important as the number of data being exchanged on the internet increases.

Nowadays steganography deals in hiding the data to provide the security to various important and crucial data. Because of this, there is change in the regularity of processing the hiding technique changes. They are more tensed and in very much pressure to earn money so this leads to various causes to trap the important information.

Data hiding system is said to be secured if we have knowledge of hiding data by using algorithm which does not help the eavesdropper to detect hidden data or know the secret data. Stego keys play an important role in improving the security of data hiding technique. As in the proposed work, two different stego keys are used, the system is said to be double protected. In order to enhance the security, in proposed work instead of combining cryptography with steganography, only steganography is used twice. The reason behind this is that National Security Agency (NSA) has developed a quantum computer that could crack most types of encryption algorithms. So if the steganography is partly defeated then secret data becomes visible which can be cracked using quantum computer. Therefore if steganography is used two times, then even if at first level steganography gets defeated then the second level will keep the secret data secured.

All these reasons lead to negligence of their data which increases the chances of being trapped. Hiding is the most essential part of securing and if it gets affected then it also affects the overall departs of the organization. The aim of proposed system is to design an automated system which would manage complete  details, organisation's history and their departmental details in a single database. Developers will use this system to keep track of the crackers admiring to them. The intentions of the proposed system are to reduce over-time pay and increase the number of crackers being trapped and that can be treated accurately.

 Many servers information systems are designed to support security issues, inventory management and generation of simple statistics. Some developers use decision support systems but are largely limited. They can answer simple queries like What is the problem to paasout the information?, How many crackers can attack and at which point?. However, they cannot answer complex queries like Who is leading the gang to control over the whole data.Servers decisions are often made based on developers intuition and experience rather than on the knowledge rich data hidden in the database. This practice leads to unwanted biases, errors and excessive software costs which affects the quality of service provided to developers.

The proposed system is that integration of developer decision support with computer-based server records could reduce cracking chances, enhance transmission safety, decrease unwanted practice variation, and improve outcome. This suggestion is promising as data hiding with stego keys, e.g., data hiding, have the potential to generate a knowledge rich environment”which can help to significantly improve the quality of transmission decisions. Quality service implies secure transmission correctly and administering the transmission perfectly. Poor hiding decisions can lead to disastrous consequences which are therefore unacceptable.

We can achieve these”results by employing appropriate computer-based information and/or decision support systems. The IT industry has huge amounts of secure transmission ways which, unfortunately, are not better to discover hidden information for effective decision making. Discovery of hidden patterns and relationships often goes unexploited. Advanced data hiding techniques can help remedy this situation. The aim of proposed system is to design an automated system which would manage complete  details, organisation's history and their departmental details in a single database. It is a prototype to hide the information using various algorithms within different types of files to enhance secure transmission. After successfully whether the server is prone to handle the proposed system which will provide with”the secure transmission to the data with the help of stego keys only known to the accessed person or admin.

Steganography become more important as more people join the cyberspace revolution.  Steganography is the art of concealing information in ways that prevents the detection of hidden messages. Stegranography include an array of secret communication methods that hide the message from being seen or discovered.

Due to advances in ICT, most of information is kept electronically. Consequently, the security of information has become a fundamental issue. Besides cryptography, streganography can be employed to secure information. In cryptography, the message or encrypted message is embedded in a digital host before passing it through the network, thus the existence of the message is unknown. Besides hiding data for confidentiality, this approach of information hiding can be extended to copyright protection for digital media: audio, video and images.

The growing possibilities of modern communications need the special means of security especially on computer network. The network security is becoming more important as the number of data being exchanged on the internet increases.  Therefore, the confidentiality and data integrity  are requires to protect against unauthorized access and use. This has resulted in an explosive growth of the field of information hiding.

Motivated  by  the  world-wide  increasing  mortality  of  cracking the data each  year  and  the availability of huge amount of data redundancy from which to extract useful knowledge, researchers have been using data hiding techniques to keep the data secure.

In watermarking applications, the message contains information such as owner identification and a digital time stamp, which usually applied for copyright protection.Fingerprint, the owner of the data set embeds a serial number that uniquely identifies the user of the data set. This adds to copyright information to makes it possible to trace any unauthorized used of the data set back to the user.

Steganography hide the secrete message within the host data set and presence imperceptible and is to be reliably communicated to a receiver. The host data set is purposely corrupted, but in a covert way, designed to be invisible to an information analysis.

Both AES and LBS algorithmsare sufficient and self explanatory in their work and give the best results when it comes to the performance, accuracy and time complexity in hiding the data. The methodology which is been discussed is that to find the codes in various file from the huge amount of data and then come up with accurate hidden data to the accessor. The expected outcome is to be able to get matched with the data provided applying the appropriate technique according to the file used.

Getting data with very severe performing steps is much more helpful than getting caught of the hidden data at any cost. The expected outcome is to be able to get data by applying the appropriate technique as the . Data Hiding helps to identify the problem from a very large and complexed corrupt datasets. As the information technology is evolving day by day data hiding techniques comes out to be important and valuable assets in the field of IT as it help us to identify the serve the best Techniques processed in several steps as follows – firstly the pattern is recognised then the it will be processed into the software. The  classification and association of the data sets is done. Then the file will be accessed through the software and the stego keys will be implemented through which we can access our data.

These techniques will eventually help us to secure  the data on the server side and helps the development sector to carry the allocated task to a new level. A vast amount of data into the file can even disturb the indexing of the file . So the data should be there in an acceptable amount.

The primary focus of my project will be on to secure the transmitted data. Each database has the same instance format. There are many techniques to evaluate this kind of problem but these algorithms are new according to the new advanced technology.

1.1 PURPOSE

This technique is chosen, because this system includes not only imperceptibility but also un-delectability by any steganolysis tool. This project is developed for hiding information in any image file. The scope of the project is implementation of steganography tools for hiding information includes any type of information file and image files and the path where the user wants to save Image and extruded file.

1.2 OBJECTIVE

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 The goal of steganography is covert communication. So, a fundamental requirement of this steganography 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.

1.3 SCOPE

This project is developed for hiding information in any image file. The scope of the project is implementation of steganography tools for hiding information includes any type of information file and image files and the path where the user wants to save Image and extruded file.

The goal 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 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 areaThis 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.

CHAPTER 2- LITERATURE REVIEW

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.

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

• Text such as null characters, just alike morse code including html and java

• 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.

STEGANOGRAPHY vs WATERMARKING

Steganography pay attention to the degree of Invisibility while watermarking pay most of its attribute to the robustness of the message and its ability to withstand attacks of removal, such as image operations(rotation, cropping, filtering), audio operations(rerecording, filtering)in the case of images and audio files being watermarked respectively.

ThoughBinary executable files can be protected by serial keys, internet searches yield serial key generators for most programs and thus serial keys alone may not be sufficient to protect a file’s copyright. Secret information inside a binary file causes a change in its execution. Even one additional instruction can cause a different execution and may crash the system. If W= {w1, ..., wm} is a Watermark, the source is first divided into ‘m’ blocks with a value of 0 or 1. If the block has wm=0, it implies an unchanged block and wm =1, implies additional statements in the source. To extract the watermark, the original binary file is compared with the marked file and statement switches are extracted. The method is simple, but not resistant to attacks.

It is a non-questionable fact that delectability of a vessel with an introduced data (steganographic  message or a watermark) is a function of the changeability function of the algorithm over the vessel.

That is the way the algorithm changes the vessel and the severity of such an operation determines with no doubt the delectability of the message, since delectability is a function of file characteristics deviation from the norm, embedding operation attitude and change severity of such change decides vessel file delectability.

A typical triangle of conflict is message Invisibility, Robustness, and Security. Invisibility is a measure of the in notability of the contents of the message within the vessel.

Security is sinominous to the cryptographic idea to message security, meaning inability of reconstruction of the message without the proper secret key material shared.

Robustness refers to the endurance capability of the message to survive distortion or removal attacks intact. It is often used in the watermarking field since watermarking seeks the persistence of the watermark over attacks, steganographic messages on the other hand tend to be of high sensitivity to such attacks. The more invisible the message is the less secure it is (cryptography needs space) and the less robust it is (no error checking/recovery introduced).The more robust the message is embedded the more size it requires and the more visible it is.

2.1 STEGANOGRAPHY TECHNIQUES

Over the past few years, numerous steganography techniques that embed hidden messages in multimedia objects have been proposed. There have been many techniques for hiding information or messages in images in such a manner that alteration made to the image is perceptually indiscernible. Commonly approaches are include LSB, Masking and filtering and Transform techniques.

Steganography provides a way to communicate secretly as long as an attacker doesn’t find a way to detect the message. The most suitable types of files for steganographic transmission being, mediafiles due to their large size. The host files concealing other files are usually called carriers. The carrier files are functional files and does not raise a question or arouse suspicion. This section lists a number of hiding techniques that are being usedpresently. Data can be embedded within a file by taking advantage of human perception. Audio files use frequency masking on tones with similar frequencies and the casual listener does not hear the masked quieter tone.

2.1.1 LEAST-SIGNIFICANT-BIT Algorithms

Least significant bit (LSB) insertion is a simple approach to embedding information in image file. The simplest steganography techniques embed the bits of the message directly into least significant bit plane of the cover-image in a deterministic sequence. Modulating the least significant bit does not result in human perceptible difference because the amplitude of the change is small. In this technique, the embedding capacity can be increased by using two or more least significant bits. At the same time, not only the risk of making the embedded message statistically detectable increase but also the image fidelity degrades. Hence a variable size LSB embedding schema is presented, in which the number of LSBs used for message embedding/extracting depends on the local characteristics of the pixel.  The advantage of LSB-based method is easy to implement and high message pay-load.

Although LSB hides the message in such way that the humans do not perceive it, it is still possible for the opponent to retrieve the message due to the simplicity of the technique. Therefore, malicious people can easily try to extract the message from the beginning of the image if they are suspicious that there exists secret information that was embedded in the image.

Therefore, a system named Secure Information Hiding System (SIHS) is proposed to improve the LSB scheme. It overcomes the sequence-mapping problem by embedding the massage into a set of random pixels, which are scattered on the cover-image.

Masking and filtering techniques, usually restricted to 24 bits and gray scale image, hide information by marking an image, in a manner similar to paper watermarks. The technique perform analysis of the image, thus embed the information in significant areas so that the hidden message is more integral to cover image than just hiding it in the noise level.

Transform techniques embed the message by modulating coefficient in a transform domain, such as the Discrete Fourier Transform, or Wavelet Transform. These methods hide messages in significant areas of the cover image, which make them more robust to attack. Transformations can be applied over the entire image, to block throughout the image, or other variant.

IMAGE STEGANOGRAPHY AND BITMAP PICTURES defines that Using bitmap pictures for hiding secret information is one of most popular choices for Steganography. Many types of software built for this purpose, some of these software use password protection to encrypting information on picture. To use these software you must have a ‘BMP’ format of a pictures to use it, but using other type of pictures like “JPEG”, “GIF” or any other types is rather or never used, because of algorithm of “BMP” pictures for Steganography is simple. Also we know that in the web most popular of image types are “JPEG” and other types not “BPM”, so we should have a solution for this problem.

This software provide the solution of this problem, it can accept any type of image to hide information file, but finally it give the only “BMP” image as an output that has hidden file inside it.

BITMAP STEGANOGRAPHY defines that the Bitmap type is the simplest type of picture because that it doesn’t have any technology for decreasing file size. Structure of these files is that a bitmap image created from pixels that any pixel created from three colors ( red, green and blue said RGB) each color of a pixel is one byte information that shows the density of that color. Merging these three color makes every color that we see in these pictures. We know that every byte in computer science is created from 8 bit that first bit is Most-Significant-Bit (MSB) and last bit Least-Significant-Bit (LSB), the idea of using Steganography science is in this place; we use LSB bit for writing our security information inside BMP pictures. So if we just use last layer (8st layar) of information, we should change the last bit of pixels, in other hands we have 3 bits in each pixel so we have 3*hight*width bits memory to write our information. But before writing our data we must write name of data(file), size of name of data & size of data. We can do this by assigning some first bits of memory (8st layer).

(00101101 00011101 11011100)

(10100110 11000101 00001100)

(11010010 10101100 01100011)

Using each 3 pixel of picture to save a byte of data.

2.1.2 ADVANCED ENCRYPTION STANDARDS  Algorithms

 AES is a symmetric key block cipher published by the NIST in December 2001.  NIST evaluation criteria for AES are  [1] Security [2] Cost [3] Algorithm and Implementation Characteristics.  AES is a non-Feistel cipher that encrypts and decrypts a data block of 128-bits.  The key size can be 128,192 or 256-bits.  It depends on number of rounds.  The input to the encryption and decryption algorithm is a single 128-bit block.  The block is represented as a row of matrix of 16 bytes. AES structure is not a Feistel structure.  Encryption is the process of converting plaintext to cipher-text (had to understand) by applying mathematical transformations.  These transformations are known as encryption algorithms and require an encryption key.  Decryption is the reverse process of getting back the original data from the cipher-text using a decryption key.  In Symmetric cryptology- The encryption key and the decryption key could be the same as in symmetric or secret key cryptography, The key can different as in asymmetric or public key cryptography.  

The existing system uses the histogram of the text file to embed the data. 

This method also enhances the contrast of the text file. The image enhancement is achieved by histogram equalisation. The highest peaks in the histogram are taken. The bins between the peaks are unchanged while the outer bins are shifted outwards so that each of the two peaks can be split into two adjacent bins. To increase embedding capacity, the highest two bins in the modified histogram can be further chosen to be split, and so on until satisfactory construct enhancement effect is achieved. For the recovery of the originaltext file , the location map is embedded into the host text file, together with the message bits and other side information. So blind data extraction and complete recovery of the original text file are both enabled. The generation of image histogram is a difficult and a time consuming process. But the contrast of the text file is enhanced. The data is only hidden in the text file where the security level is simple. Since the data is hidden and if the retrieving process is known the intruder will be able to retrieve the text file easily without any effort.

A. Disadvantages in existing system

• High Computation time.  • Algorithm Complexity and distortion is high.  • Security is less because single key is used for the whole process. • Generation of histogram is a difficult and time consuming process.

  The distributed source coding (DSC) to encrypt text file in RDH, by encrypting the original text file/media using stream cipher, the data-hider compresses a series of selected bits which is taken from the encrypted text file to make the secret data.  The original text file is encrypted directly by the sender and the data-hider embeds the additional bits by modifying some bits of the encrypted data.  Data extraction and text file recovery are realized by analyzing the local standard deviation during decryption of the marked encryptedtext file . The receiver end has both the embedding and encryption key and then the receiver can extract the secret data and recover the original text file perfectly using the distributed source decoder. 

 The expected result is lossless text file and data. Thus in our project the security of the text file can be enhanced by encrypting the data and the image in which the data is hidden. The receiver should have three keys to retrieve the data (i.e.) the decryption key of the data, the retrieving key of the data from the image and lastly the decrypting key of the text file.

The Developers implemented a variation of plain LSB (Least Significant Bit) algorithm. The stego-image quality has been improved by using bit-inversion technique. LSB method improving the PSNR of stegoimage. Through storing the bit patterns for which LSBs are inverted, image may be obtained correctly. For the improving the robustness of steganography, RC4 algorithm had been implemented to achieve the randomization in hiding message image bits into cover image pixels instead of storing them sequentially.

 This method randomly disperses the bits of the message in the cover image and thus, harder for unauthorized people to extract the original message. The presented method shows good enhancement to Least Significant Bit technique in consideration to security as well as image quality. It was Investigated on Medical records are extremely sensitive patient information a multi secure and robustness of medical image based steganography scheme is proposed. This methodology provides an efficient and storage security mechanism for the protection of digital medical images. Authors proposed a viable steganography method using Integer Wavelet Transform to protect the MRI medical image into a single container image. The patient's medical diagnosis image has been taken as secret image and Arnold transform was applied and scrambled secret image was obtained. In this case, the scrambled secret image was embedded into the dummy container image and Inverse IWT was taken to get a dummy secret image. It has been observed that the quality parameters are improved with acceptable PSNR compared to the existing algorithms.

the novel scheme embeds data in integer wavelet transform coefficients by using a cropping function in an 8×8 block on the cover image. The optimal pixel change process has been applied after embedding the message. Authors employed the frequency domain to increase the robustness of our steganography method. Integer wavelet transform avoid the floating point precision problems of the wavelet filter. Result shows that the method outperforms adaptive steganography technique based on integer wavelet transform in terms of peak signal to noise ratio and capacity. In the year of 2012 Das, R. and Tuithung, T. [5] proposed a novel technique for image steganography based on Huffman Encoding. Two 8 bit gray level image of size M X N and P X Q are used as cover image and secret image respectively. Huffman Encoding is performed over the secret image/message before embedding and each bit of Huffman code of secret image/message is embedded inside the cover image by altering the least significant bit (LSB) of each of the pixel's intensities of cover image. Th e size of Huffman encoded bit stream and Huffman Table are also embedded inside the cover image, in order that the Stego-Image becomes standalone information to the receiver. Results show that the algorithm has a high capacity and a good invisibility. Moreover Peak Signal to Noise Ratio (PSNR) of stego image with cover image shows better result in comparison with other existing steganography approaches. The satisfactory security is maintained in this research. is used to hide the key thus it is very secure and robust because no one can realize the hidden information and it cannot be lost due to noise or any signal processing operations. Result shows very good Peak Signal to Noise Ratio, which is a measure of security. In this method the secret information is hidden in the middle bit-planes of the integer wavelet coefficients in high frequency sub-bands. Secure steganography is used to hide. 

Secure Steganography using Hybrid Domain Technique (SSHDT). The cover image of different formats and sizes are considered and resized to dimensions of power of 2. The Daubechies Lifting Wavelet Transforms is applied on cover image to generate four sub bands. The XD band is considered and divided into two equal blocks say upper and lower for payload embedding. The payload of different formats are considered and resized to dimensions of power of 2. The payload is fragmented into four equal blocks. The Decision Factor Based Manipulation is used to scramble further stego object to improve security to the payload. Dubechies Inverse LWT is applied on stego objects to obtain stego image in spatial domain. It has been observed that PSNR and embedding capacity of the proposed algorithm is better compared to the existing algorithm.

With the rapid development of internet and wide application of multimedia technology, people can communicate the digital multimedia information such as digital image, with others conveniently over the internet. 

In numerous cases, image data, transmitted over a network are expected not to be browsed or processed by illegal receivers. Consequently, the security of digital image has attracted much attention recently and many different methods for image encryption have been proposed, such as Optical systems are of growing interest for image encryption because of their distinct advantages of processing 2-dimensional complex data in parallel at high speed. In the past, many optical methods have been proposed. Among them the most widely used and highly successful optical encryption scheme is double random phase encoding proposed. It can be shown that if these random phases are statistically independent white noise then the encrypted image is also a stationary white noise. In some schemes chaos based functions are used to generate random phase mask. Such as the generalization of the conventional Fourier transform.

In steganography, the message is embedded into the digital media rather than encrypting it. The digital media contents, called the cover, can be determined by anybody, the message hidden in the cover can be detected by the one having the true key. The message in the message after the receiver gets the data. That allows steganography to protect the embedded information after it is decrypted. Steganography is therefore broader than cryptography.

 Signal processing area includes- filtering, de-noising method, interference suppression, radar signal processing, electromagnetic wave propagation, and wireless communication systems. The area of the image processing applications includes steganography.

The work is concerned with implementing Steganography for images, with an improvement in both security and image quality. The one that is implemented here is a variation of plain LSB (Least Significant Bit) algorithm. The stego-image quality is improved by using bit-inversion technique. In this technique, certain least significant bits of cover image are inverted after LSB steganography that co-occur with some pattern of other bits and that reduces the number of modified LSBs. Thus, less number of least significant bits of cover image is altered in comparison to plain LSB method, improving the PSNR of stegoimage. By storing the bit patterns for which LSBs are inverted, message image can be obtained correctly. To improve the robustness of steganography, RC4 algorithm has been used to achieve the randomization in hiding message image bits into cover image pixels instead of storing them sequentially. This process randomly disperses the bits of the message in the cover image and thus, making it harder for unauthorized people to extract the original message. The proposed method shows good enhancement to Least Significant Bit technique in consideration to security as well as image quality.

CHAPTER 3- METHODOLOGY

Steganography system requires any type of image file and the information or message that is to be hidden. It has two modules encrypt and decrypt.

Microsoft .Net framework prepares a huge amount of tool and options for programmers that they simples programming. One of .Net tools for pictures and images is auto-converting most types of pictures to BMP format. I used this tool in this software called “Steganography” that can use this software to hide your information in any type of pictures without any converting its format to BMP (software converts inside it).

The algorithm used for Encryption and Decryption in this application provides using several layers lieu of using only LSB layer of image. Writing data starts from last layer (8st or LSB layer); because significant of this layer is least and every upper layer has doubled significant from its down layer. So every step we go to upper layer image quality decreases and image retouching transpires.

The encrypt module is used to hide information into the image; no one can see that information or file. This module requires any type of image and message and gives the only one image file in destination.

The decrypt module is used to get the hidden information in an image file. It take the image file as an output, and give two file at destination folder, one is the same image file and another is the message file that is hidden it that.

Before encrypting file inside image we must save name and size of file in a definite place of image. We could save file name before file information in LSB layer and save file size and file name size in most right-down pixels of image. Writing this information is needed to retrieve file from encrypted image in decryption state.

Text steganography can be achieved by altering the text formatting, or by altering certain characteristics of textual elements (e.g., characters). The goal in the design of coding methods is to develop alterations that are reliably decodable (even in the presence of noise) yet largely indiscernible to the reader. These criteria, reliable decoding and minimum visible change, are somewhat conflicting; herein lies the challenge in designing document marking techniques. The document format file is a computer file describing the document content and page layout (or formatting), using standard format description languages such as PostScript2, TeX, @off, etc. It is from this format file that the image - what the reader sees - is generated. The three coding techniques that we propose illustrate different approaches rather than form <an exhaustive list of document marking techniques. The techniques can be used either separately or jointly. Each technique enjoys certain advantages or applicability as we discuss below. Line-Shift Coding This is a method of altering a document by vertically shifting the locations of text lines to encode the document uniquely. This encoding may be applied either to the format file or to the bitmap of a page image. The embedded codeword may be extracted from the format file or bitmap. In certain cases this decoding can be accomplished without need of the original image, since the original is known to have uniform line spacing between adjacent lines within a paragraph. Word-Shift Coding This is a method of altering a document by horizontally shifting the locations of words within text lines to encode the document uniquely. This encoding can be applied to either the format file or to the bitmap of a page image. Decoding may be performed from the format file or bitmap. The method is applicable only to documents with variable spacing between adjacent words. Variable spacing in text documents is commonly used to distribute white space when justifying text. Because of this variable spacing, decoding requires the original image - or more specifically, the spacing between words in the un-encoded document. Feature Coding This is a coding method that is applied either to a format file or to a bitmap image of a document. The image is examined for chosen text features, and those features are altered, or not altered, depending on the codeword. Decoding requires the original image, or more specifically, a specification of the change in pixels at a feature. There are many possible choices of text features; here, we choose to alter upward, vertical endlines - that is the tops of letters, b, d, h, etc. These endlines are altered by extending or shortening their lengths by one (or more) pixels, but otherwise not changing the endline feature.  There is another form of text steganography which is defined by Chapman et al. as the text steganography is a method of using written natural language to conceal a secret message.

Hiding information inside images is a popular technique nowadays. An image with a secret message inside can easily be spread over the World Wide Web or in newsgroups. The use of steganography in newsgroups has been researched by German steganographic expert Niels Provos, who created a scanning cluster which detects the presence of hidden messages inside images that were posted on the net. However, after checking one million images, no hidden messages were found, so the practical use of steganography still seems to be limited. To hide a message inside an image without changing its visible properties, the cover source can be altered in ”noisy” areas with many color variations, so less attention will be drawn to the modifications. The most common methods to make these alterations involve the usage of the least-significant bit or LSB, masking, filtering and transformations on the cover image. These techniques can be used with varying degrees of success on different types of image files.

A simple approach for embedding information in cover image is using Least Significant Bits (LSB). The simplest steganography techniques embed the bits of the message directly into least significant bit plane of the cover image in a deterministic sequence. Modulating the least significant bit does not result in human-perceptible difference because the amplitude of the change is small [9]. To hide a secret message inside an image, a proper cover image is needed. Because this method uses bits of each pixel in the image, it is necessary to use a lossless compression format, otherwise the hidden information will get lost in the transformations of a lossy compression algorithm. When using a 24-bit color image, a bit of each of the red, green and blue color components can be used, so a total of 3 bits can be stored in each pixel. For example, the following grid can be considered as 3 pixels of a 24-bit color image.

ENCRYPTION IN IMAGE

Encryption is the process of encoding a message or information in such a way that only authorized parties can access it and those who are not authorized cannot. Encryption does not itself prevent interference, but denies the intelligible content to a would-be interceptor. In an encryption scheme, the intended information or message, referred to as plaintext, is encrypted using an encryption algorithm that can be read only if decrypted. For technical reasons, an encryption scheme usually uses pseudo-random encryption key generated by an algorithm. It is in principle possible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users.

At the first step to accessinto the system for hiding the data, the users are needed a username and password. After login the system, user can write the message to encrypt the data with the secret keysbefore embedding the data into an image as demonstrate in figure 1. In our system the proposed scheme uses Affine algorithm to encrypt secret information. Affine cipher is one of the algorithmsthat have used to encrypt data. In this process wherein each letter in an alphabet is mapped to its numeric equivalent, encrypted using a mathematical function, and converted back to a letter. The formula used means that each letter encrypts to one other letter, and back again, meaning the cipher is essentially a standard substitution cipher with a rule governing which letter goes to which. This technique provides better security to protect the data user from the unauthorized access over a network due to which will not be easy to retrieve the data without the recipient key. 

We have to write the encoded part in the space given. Here we can access the image in which we can hide our important and crucial data so that we can transfer it to the receiver who can decode it. The next step is shown below:

Here we accessed  the data which have be hidden. We have to select our image in which we have to hide the data through the steganography techniques. We can easily access with the help of stego keys through which the image can be easily decrypted at the receivers end.

DECRYPTION IN IMAGE

Decryption is the process of decoding encrypted information so that is can be accessed again by authorized users. Decryption is generally the reverse process of encryption. It is the process of decoding the data which has been encrypted into a secret format. An authorized user can only decrypt data because decryption requires a secret key or password. In the decrypt phase to detect the positions of the LSB’s where the data bits had been embedded we have again used the hash function. In the same order as they are embedded, the bits are extracted from the position when the position of the bits had been specified. At the end of this phase we will obtain the secret message in binary form which gain converted into ASCII code form then the ASCII code form will be converted into cipher text, finally the receiver will decrypt secret message by using Affine cipher key

Here we can select the image which we have to decode. It can easily get linked with the software where we have to decode it.

Here we got the encrypted file which we can easily decode it by clicking the decode button. 

ENCRYPTION IN TEXT

Encryption is the process of encoding a message or information in such a way that only authorized parties can access it and those who are not authorized cannot. Encryption does not itself prevent interference, but denies the intelligible content to a would-be interceptor. In an encryption scheme, the intended information or message, referred to as plaintext, is encrypted using an encryption algorithm that can be read only if decrypted. For technical reasons, an encryption scheme usually uses pseudo-random encryption key generated by an algorithm. It is in principle possible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users.

We have to write the encoded part in the space given. Here we can access the image in which we can hide our important and crucial data so that we can transfer it to the receiver who can decode it. The next step is shown below:

Here we accessed  the data which have be hidden. We have to select our text file in which we have to hide the data through the steganography techniques. We can easily access with the help of stego keys through which the image can be easily decrypted at the receivers end.

Here we accessed  the data which have be hidden. We have to select our text file in which we have to hide the data through the steganography techniques. We can easily access with the help of stego keys through which the text file can be easily decrypted at the receivers end.

It is in principle possible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users.

DECRYPTION IN TEXT FILE

Decryption is the process of decoding encrypted information so that is can be accessed again by authorized users. Decryption is generally the reverse process of encryption. It is the process of decoding the data which has been encrypted into a secret format. An authorized user can only decrypt data because decryption requires a secret key or password.

Here we can select the text file which we have to decode. It can easily get linked with the software where we have to decode it.

Here we got the final decrypted text which was encrypted in the text file. The final result screenshot is shown below:

Here we got the resultant code which we have encrypted. 

We have shown the steganography within both image file and text file. We have got the result with easy access for secure transmission. Both Least Significant Bit Algorithm for image file and Advanced Encryption Standards Algorithm for text file. 

CHAPTER 4 - APPLICATIONS

Steganography is applicable to, but not limited to, the following areas. 

1. Confidential communication and secret data storing 

2. Protection of data alteration 

3. Access control system for digital content distribution 

4. Media Database systems  

The area differs in what feature of the steganography is utilized in each system. 

The "secrecy" of the embedded data is essential in this area. 

Historically, steganography have been approached in this area. Steganography provides us with: 

• Potential capability to hide the existence of confidential data 

• Hardness of detecting the hidden (i.e., embedded) data 

• Strengthening of the secrecy of the encrypted data 

In practice, when you use some steganography, you must first select a vessel data according to the size of the embedding data. The vessel should be innocuous. Then, you embed the confidential data by using an embedding program (which is one component of the steganography software) together with some key. When extracting, you (or your party) use an extracting program (another component) to recover the embedded data by the same key ("common key" in terms of cryptography). In this case you need a "key negotiation" before you start communication. 

Attaching a stego file to an e-mail message is the simplest example in this application area. But you and your party must do a "sending-and-receiving" action that could be noticed by a third party. So, e-mailing is not a completely secret communication method.There is an easy method that has no key-negotiation. There is some other communication method that uses the Internet Webpage. In this method you don't need to send anything to your party, and no one can detect your communication. 

Each secrecy based application needs an embedding process which leaves the smallest embedding evidence. You may follow the following. 

• Choose a large vessel, larger the better, compared with the embedding data. 

• Discard the original vessel after embedding. 

PROTECTION OF DATA STORAGE

We take advantage of the fragility of the embedded data in this application area. "the embedded data can rather be fragile than be very robust." Actually, embedded data are fragile in most steganography programs. However, this fragility opens a new direction toward an information-alteration protective system such as a "Digital Certificate Document System." The most novel point among others is that 

"no authentication bureau is needed." If it is implemented, people can send their "digital certificate data" to any place in the world through Internet. No one can forge, alter, nor tamper such certificate data. If forged, altered, or tampered, it is easily detected by the extraction program.   

ACCESS CONTROL SYSTEM FOR DIGITAL CONVENTION

In this area embedded data is "hidden", but is "explained" to publicize the content. 

Today, digital contents are getting more and more commonly distributed by Internet than ever before. For example, music companies release new albums on their Webpage in a free or charged manner. However, in this case, all the contents are equally distributed to the people who accessed the page. So, an ordinary Web distribution scheme is not suited for a "case-by-case" and "selective" distribution. Of course it is always possible to attach digital content to e-mail messages and send to the customers. But it will takes a lot of cost in time and labor. 

If you have some valuable content, which you think it is okay to provide others if they really need it, and if it is possible to upload such content on the Web in some covert manner. And if you can issue a special "access key" to extract the content selectively, you will be very happy about it. A steganographic scheme can help realize a this type of system.We have developed a prototype of an "Access Control System" for digital content distribution through Internet. The following steps explain the scheme. 

• A content owner classify his/her digital contents in a folder-by-folder manner, and embed the whole folders in some large vessel according to a steganographic method using folder access keys, and upload the embedded vessel (stego data) on his/her own Webpage. 

• On that Webpage the owner explains the contents in depth and publicize worldwide. The contact information to the owner (post mail address, e-mail address, phone number, etc.) will be posted there.  

• The owner may receive an access-request from a customer who watched that Webpage. In that case, the owner may (or may not) creates an access key and provide it to the customer (free or charged). In this mechanism the most important point is, a "selective extraction" is possible or not. 

MEDIA DATABASE SYSTEM

In this application area of steganography secrecy is not important, but unifying two types of data into one is the most important.   

Media data (photo picture, movie, music, etc.) have some association with other information. A photo picture, for instance, may have the following. 

• The title of the picture and some physical object information 

• The date and the time when the picture was taken 

• The camera and the photographer's information 

Formerly, these are annotated beside the each picture in the album. 

Recently, almost all cameras are digitalized. They are cheap in price, easy to use, quick to shoot. They eventually made people feel reluctant to work on annotating each picture. Now, most home PC's are stuck with the huge amount of photo files. In this situation it is very hard to find a specific shot in the piles of pictures. A "photo album software" may help a little. You can sort the pictures and put a couple of annotation words to each photo. When you want to find a specific picture, you can make a search by keywords for the target picture. However, the annotation data in such software are not unified with the target pictures. Each annotation only has a link to the picture. 

Therefore, when you transfer the pictures to a different album software, all the annotation data are lost. 

This problem is technically referred to as "Metadata (e.g., annotation data) in a media database system (a photo album software) are separated from the media data (photo data) in the database managing system (DBMS)." This is a big problem. 

Steganography can solve this problem because a steganography program unifies two types of data into one by way of embedding operation. So, metadata can easily be transferred from one system to another without hitch. Specifically, you can embed all your good/bad memory (of your sight-seeing trip) in each snap shot of the digital photo. You can either send the embedded picture to your friend to extract your memory on his/her PC, or you may keep it silent in your own PC to enjoy extracting the memory ten years after.  

If  a "motion picture steganography system" has been developed in the near future, a keyword based movie-scene retrieving system will be implemented. It will be a step to a "semantic movie retrieval system." 

USAGE IN MODERN PRINTERS

Steganography is used by some modern printers, 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. 

EXAMPLE FOR MODERN PRACTICE

The larger the cover message is (in data content terms—number of bits) relative to the hidden message, the easier it is to hide the latter. For this reason, digital pictures (which contain large amounts of data) are used to hide messages and on other communication media. It is not clear how commonly this is actually done. For example: a 24-bit bitmap will have 8 bits representing each of the three color values (red, green, and blue) If we consider just the blue there will be 28 different values of blue. The difference between 11111111 and 11111110 in the value for blue intensity is likely to be undetectable by the human eye. Therefore, the Least significant bit can be used (more or less undetectably) for something else other than color information. If we do it with the green and the red as well we can get one letter of ASCII text for every three pixels. 

Stated somewhat more formally, the objective for making steganographic encoding difficult to detect is to ensure that the changes to the carrier (the original signal) due to the injection of the payload (the signal to covertly embed) are visually (and ideally, statistically) negligible; that is to say, the changes are indistinguishable from the noise of the carrier. Any medium can be a carrier, but media with a large amount of redundant or compressible information are better suited. 

This means that the channel must have more  than the "surface” requires for a digital image, this may be from the imaging element; for digital it may be noise from recording techniques or amplification equipment. In general, electronics that digitize a signal suffer from several noise sources such as. This noise provides enough variation in the captured digital information that it can be exploited as a noise cover for hidden data. In addition, schemes  always introduce some error into the decompressed data; it is possible to exploit this for steganographic use as well. 

Steganography can be used for digital watermarking, where a message (being simply an identifier) is hidden in an image so that its source can be tracked or verified), or even just to identify an image. 

ALLEGED USE BY TERRORISTS

When one considers that messages could be encrypted steganographically in e-messages, particularly e-mail spams the notion of junk e-mail takes on a whole new light. Coupled with the chaffing and winnowing" technique, a sender could get messages out and cover their tracks all at once. 

 An example showing how terrorists may use forum avtars to send 

hidden messages. This avatar contains the message "Boss said that we should blow up the bridge at midnight." Rumors about terrorists using steganography started first in the daily newspaper USA Today on February 5, 2001 in two articles titled "Terrorist instructions hidden online" and "Terror groups hide behind Web encryption". In July the same year, an article was titled even more precisely: "Militants wire Web with links to jihad". A citation from the articleOther media worldwide cited these rumors many times, especially after the terrorist attack of 9/11, without ever showing proof. The Italian newspaper reported that an Al Qaeda cell which had been captured at the Via Quaranta mosque in Milan had pornographic images on their computers, and that these images had been used to hide secret messages (although no other Italian paper ever covered the story). The USA Today articles were written by veteran foreign correspondent , who in 2004 was fired after allegations emerged that he had fabricated stories and sources. 

In October 2001, New York Times published an article claiming that al-Qaeda had used steganography to encode messages into images, and then transported these via email and possibly to prepare and execute the September 11, 2001 Terrorist Attack. The Federal Plan for Cyber Security and Information Assurance 

Research and Development, published in April 2006 makes the following statements: 

"...immediate concerns also include the use of cyberspace for covert communications, particularly by terrorists but also by foreign intelligence services; espionage against sensitive but poorly defended data in government and industry systems; subversion by insiders, including vendors and contractors; criminal activity, primarily involving fraud and theft of financial or identity information, by hackers and organized crime groups..." 

"International interest in R&D for steganography technologies and their commercialization and application has exploded in recent years. These technologies pose a potential threat to national security. Because steganography secretly embeds additional, and nearly undetectable, information content in digital products, the potential for covert dissemination of malicious software, mobile code, or information is great."  

"The threat posed by steganography has been documented in numerous intelligence reports."  

Moreover, an online "terrorist training manual", the "Technical Mujahid, a Training 

Manual for Jihadis" contained a section entitled "Covert Communications and Hiding Secrets Inside Images." 

Al Qaeda's use of steganography is somewhat simpler: In 2008 a British Muslim, Rangzieb Khan, was alleged to have a contact book with Al-Queda telephone numbers, written in invisible ink. He was convicted of terrorism. 

CHAPTER 5 – CONCLUSION

To hide confidential information steganography can be effectively used. The objective of any Steganographic method is to hide maximum secret information which is immune to external attacks and also should not convey the fact that the cover medium is carry secret information. This thesis has used LSB substitution technique for time domain and different transforms for frequency domain.

The random key made use of while LSB technique is employed has proved to be better than simple LSB substitution. When the personal is key is made use of in the techniques have not altered the resolution of the image much and appears to be negligible as been seen with the obtained results. Hence the hidden data getting damaged buy the third person is almost impossible. The algorithm can be implemented in both grayscale and color image since it has made use of 8 bit and 24bit images of size for both cover and secret image.

In Spatial domain methods one can get high payload capacity. The edge detection techniques which are used in the current methods do not recognizes the shades of the edge region, which can also be considered to embed the extra bits. The number of edge pixels can be increased by identifying the edges and shades of edges.

The Transform domain methods are highly robust. They embed the message bits in the regions which are highly insensitive to compression, filtration or transformation. But their payload capacity is low. Also the visual qualities of the Stego-image are poor. Spatial domain is better compared to transform domain.

In Spatial Domain techniques simple LSB substitution methods are less secure and payload capacity is less. To increase security Randomization techniques are used. These methods spread the message randomly into the cover image but payload capacity is still less. Edge detection method increases the payload capacity and it improves randomness and hence security. 

As discussed the current edge detection methods do not recognizes the shades of the edge region which are also capable of embedding more bits with less distortion. The shades of the edges are detected by Multiple Edge Detection method. In Multiple Edge Detection method the edge detection method is applied for 2-3 times which increase the number of edge pixels. As the number of edge pixels is increased more data can be hidden in to the cover image. 

To add randomness to the embedding procedure which increases security, Variable Embedding can be employed in which a suitable embedding ratio is chosen and according to that the message bits are embedded into the image pixels. The increase in the payload decrease PSNR value, which indicates image degradation amount. To improve PSNR Minimum Error Replacement method is used. In this method the next higher bit than the last embedded bit is toggle to decrease the pixel error.

Stego and crypto way shows new way of embedding the data, especially in Multiresolution analysis, there are different ways of getting Multiresolution; this thesis has made use of Multiresolution analysis on wavelets and Curvelets. The experimental analysis has proved that Curvelets is the best Multiresolution transformation available. This work has been implemented with the library which has an accuracy of 15 fractional digits. The results obtained have a good PSNR value, along with the crypto style of embedding.

Steganography is to create secrete communication, in addition to this crypto way of embedding gives us higher end of security. Even if the person gets both stego and cove image he needs key to retrieve the data, without the key one can’t recover the data. Thus additional security is incorporated to the normal Steganography technique.Image steganography is successfully obtained for different embedding techniques in both wavelet and curvelet domain. Depending on the demand of the application one can choose any of the techniques developed. The simulations are performed in MatLab 7.7.0(R2008b) and PSNR are calculated. It is found that Curvelet is a better approach than wavelet transformation. In this work data embedding is done by considering block of size.

In the frequency domain technique use of skin tone algorithm has given very good results. The proposed method uses skin tone detection for finding skin portion of image and within this skin portion secret data embedding is done using DWT domain. 

Four cases of embedding are considered. It is observed that hiding of secret data in only the cropped skin portion enhances the security. And according to result and discussion proposed scheme provides good image quality in all four cases.

In Transform domain methods the pay load capacity is low and the future scope is to enhance Stego image quality and payload capacity. The payload capacity can still be increased by embedding more bits into edge pixels and less to non edge pixels. Future Enhancement can be done by embedding data pixel by pixel, thus increase in the payload can be attained.

CHAPTER 6 – FUTURE ENHANCEMENT

In this work it explores only a small part of the science of steganography. As a new displine, there is a great deal more research and development to do,

The following section describe areas for research which were offshoots of, or tangential to,our main objectives.

Detecting Steganography in Image Files

Can steganography be detected in images files? This is difficult question. It may be possible to detect a simple Steganographic technique by simple analyzing the low order bits of the image bytes. If the Steganographic algorithm is more complex, however, and spreads the embedded data over the image is random way or encrypts the data before embedding, it may be nearly impossible to detect.

1. How widespread is the Use of Steganography?

If a technique or set of techniques could be devised to detect steganography, it

would be interesting to conduct a survey of images available on the internet to determine if steganography is used, by whom and for what purposes. Steganographic applications are available on the Internet, but it is not known if they are being used.

2. Steganography on the World Wide Web

The world wide web(www) makes extensive use of inline images.There are literally millions of images on various web pages worldwide. It may be possible to develop an application to serve as a web browser to retrieve data embedded in web page images. This “ stego-web” could operate on top of the existing WWW and be a means of covertly disseminating information.

3. Steganography in printed media.

If the data is embedded in an image, the image printed, then scanned and stored in a file can the embedded data be recovered? This would require a special form of a steganography to which could allow for in accuracies in the printing and scanning equipment.

4. Anti-steganography measures

As was seen in this thesis, JPEG garbles any unencoded steganographically embedded data. Also, palettization (mapping a large number of colors in an image to a smaller subset of colors) of an image will it unsuitable for steganography. It is likely, as with JPEG, that some means may be employed to prevent loss of steganographically embedded data when its wrapper file is processed. The question remains open as to what is the most effective anti Steganographic tools or set of tools.

This report   provides   an   overview   of   steganalysis   and   introduced   some characteristics of steganographic software that point signs of information hiding. This work  is  but  a  fraction  of  the  steganalysis  approach.  To  date  general  detection techniques  as  applied  to  steganography  have  not  been  devised  and  methods  beyond visual  analysis  are  being  explored.  Too  many  images  exist  to  be  reviewed  manually for  hidden  messages  so  development  of  a  tool  to  automate  the  process  will  be beneficial  to  analysts.  The  ease  in  use  and  abundant  availability  of  steganography tools  has  law  enforcement  concerned  in  trafficking  of  illicit  material  via  web  page images, audio, and other transmissions over the Internet. Methods  of   message  detection  and understanding  the  thresholds  of  current technology  are  under  investigation.  Success  in  steganographic  secrecy  results  from selecting  the  proper  mechanisms.  However,  a  stegomedium  which  seems  innocent enough may, upon further investigation, actually broadcast the existence of embedded information.Development  in  the  area  of  covert  communications  and  steganography  will continue.   Research   in   building   more   robust   methods   that   can   survive   image manipulation  and  attacks  continues  to  grow.  The  more  information  is placed  in  the public's  reach  on  the  Internet,  the  more  owners  of  such  information  need  to  protect themselves   from   theft   and   false   representation.   Systems   to   recover   seemingly destroyed  information and steganalysis techniques will  be useful to law enforcement authorities in computer forensics and digital traffic analysis.Most  data-hiding  systems  take  advantage  of  human  perceptual  weaknesses,  but have  weaknesses  of  their  own.  For  now,  it  seems  that  no  system  of  data-hiding  is totally immune to attack. However,  steganography  has  its  place  in  security.  It  in  no  way  can  replace cryptography,  but  is  intended  to  supplement  it.  Its  application  in  watermarking  and fingerprinting,  for  use  in  detection  of  unauthorized,  illegally  copied  material,  is continually being realized and developed.

Also,   in   places   where   standard   cryptography   and   encryption   is   outlawed, steganography can be used for covert data transmission. Steganography, formerly just an  interest  of  the  military,  is  now  gaining  popularity  among  the  masses.  Soon,  any computer user will be able to put his own watermark on his artistic creations.

CHAPTER 7 - SUMMARY

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.

Since ancient times, man has found a desire in the ability to communicate covertly. The recent explosion of research in watermarking to protect intellectual property is evidence that steganography is not just limited to military or espionage applications. Steganography, like cryptography, will play an increasing role in the future of secure communication in the “digital world”.

 With this project I have learned a lot, especially about bit operations and bit-masking, something that I never understood before. This project was fun from the start and only got more interesting as I went on developing it. I became more interested in the subject the more I researched it.I have learned that while implementing Image Steganography is important, thinking of how to detect and attack it and the methods to do so are far more complex than actually doing the Steganography itself. There is a lot of research that is beginning to discover new ways to detect Steganography, most of which involves some variation of statistical analysis. It is interesting to see what other methods will be developed and how accurate they will be at detecting Steganography.

Steganography today, then again, is altogether more complex, permitting a client to conceal a lot of data inside picture and sound documents. These types of steganography regularly are utilized as a part of conjunction with cryptography so that the data is doubly secured; first it is encoded and afterward shrouded so that an enemy needs to first find the data (a frequently troublesome assignment all by itself) and afterward decode it. Appropriately, cryptography is not the great 

answer for secure correspondence yet just piece of the arrangement. Both procedures can be utilized together to better ensure data . The model comprises of Carrier (C), Secret Data (D), and Stego Key (K). Transporter is the spread question in which the mystery message is implanted. Mystery information can be any sort of secret information i.e. plain content, figure content or other picture. Key primarily used to guarantee that just beneficiary having the interpreting key will have the capacity to recover the mystery message from the spread article.

 With the assistance of installing calculation, the mystery information is inserted into the spread question in a manner that does not change the first picture in a human noticeable manner. At long last, the stego object which is the yield of the methodology is only the spread article with installed mystery information. The exploration of securing an information by encryption is Cryptography though the strategy for concealing mystery messages in different messages is Steganography, so that the mystery's extremely presence is covered.