Data Hiding In Multimedia Computer Science Essay

With todays modern technology-driven universe, multimedia have brought approximately enormous alterations in our societal life. Now, multimedia puts concern, communicating, instruction, socialisation, practical world, amusements at our fingertips. Human existences are wholly surrounded by multimedia environments and accordingly multimedia has created new weighty security challenges and great advanced chances.

This study reveals the facets sing the information concealment through multimedia elements like audio signals, picture signals, text and images maintaining head in both practical and theoretical attacks. Digital information concealment is the new manner of secret communicating engineering. One of the cardinal attacks of informations concealing in multimedia is steganography and the modern attack is Digital watermarking.

A cryptography is the technique of concealing the messages utilizing such a manner that no 1 else can construe the content of the message except the transmitter and the receiver. Steganography has an beginning from the Greek word “ Steganos ” which means covered or protected message and is still in usage. There are plentifulness of techniques that are familiar to us runing from unseeable ink to trap punctures. The usage of cryptography has been passed for coevalss but the chief applications were military and intelligence intents.

The digital watermarking plays a really indispensable function in placing the ownership of the right of first publications of the embedded signals such as audio signals or image informations. A digital watermarking is nil but a procedure of concealing computing machine aided enlightening informations in a bearer signal. A digital water line is a manner of taging covertly which is added into another noise tolerant signal. The chief applications of digital watermarking are to verify the mandate or unity of the bearer signal and to place the proprietor of the signal.

Table of contents

1. Abstractaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 1

2. Introduction aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 3

2.1 Categorization of multimedia aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 3

3. Literature Reviewaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦..aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 4

4. Research Sectionaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 5

4.1 Data concealment in Imagesaˆ¦aˆ¦aˆ¦aˆ¦.aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.. 6

4.2 Steganography in JPEG imagesaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 6

4.3 Data concealment in Videoaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 8

4.4 Data concealment in Audio aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 9

5. Decision and Recommendationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 10

6. Referencesaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.. 10

List of figures

The basic model of informations concealing in multimediaaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦5

2.1 Block diagram of implanting and extraction procedure in binary imagesaˆ¦aˆ¦aˆ¦aˆ¦.6

2.2 ( a ) Test Imageaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 7

2.2 ( B ) Stego imageaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 8

3.1 Block diagram of proposed picture informations concealment systemaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.8

3.2 Schemes for managing frame jitteringaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.9

4.1 Audio signal Embedding processaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.9

2. Introduction

The term Multimedia is nil new to the human existences. Since the being of human existences multimedia has ever around us. Every individual, no affair in which age, has someplace involved in multimedia. Peoples runing from all ages has enjoyed multimedia elements such as presentations, Animations, sketch movies and presents, picture tape, compact discs, digital picture phonograph record, bluish beam and many more since their childhood yearss. An earlier individual used to cover with Analogue-multimedia and now as the engineering is altering at the light velocity now they start entertaining their egos by the originative and advanced digital-technology. The chief virtue of Analogue multimedia over the digital multimedia is that digital media allows redacting, uniting, administering of enlightening informations which is beyond the restriction of linear multimedia. The multimedia are sometimes called as “ assorted multimedia ” or the system that provides the manner of communicating by utilizing a broad scope of media effects. The word multimedia is a combination of two words ; multi and media ; multi means plural or many and media resembles medium of communicating. In Simple words, The Multimedia are nil but the meaningful combination of text, sounds, artworks, pictures, images, life which can be used for the widest scope of applications such as for communicating amusements, instructions, preparations, concerns, e-commerce, and finally for the web applications. Furthermore, the term synergistic multimedia means the rich multimedia, which is used to convey the enlightening informations in a really entertaining manner.

2.1Classification of Multimedia

Basically, multimedia can be loosely classified on the footing of timeline and beginning as: –

Captured Media

Processed Media

Continuous Media

Non-linear Media

Captured media is correspondent to the enlightening informations gathered from the existent universe For case, still images or dynamic image, different signifiers of sounds etc. Whereas processed media refers to the media which is synthesized by agencies of calculating devices such as text, artworks and computing machine life. On the other manus, Continuous Media resembles to the media which is based on clip. Sound rolled images, life are the best illustrations of uninterrupted media. Continuous media are besides named as dynamic media or clip dependent media whilst, the media which includes infinite and dimension are known as non-linear media. Largely, Non-linear media is many times referred as non-time based media or non-temporal media. However ; there are tonss of onslaughts and countermeasures for multimedia. Plenty of applications are designed for concealing multimedia contents like ownership protection, patent ownership, watchword protection, transcript or entree limitations and hallmarks. The most indispensable factor is to prove the hardiness and security of multimedia contents concealing through the onslaughts. In a wide sense it has more significance than the designing of the multimedia contents.

3. Literature Reappraisal

“ With the progresss of the digital information revolution and the social alterations they have prompted, it has become critical to ease the unafraid direction of content use and bringing across communicating webs ” . ( MIN WU and Bede Liu, 2003 ) . The surveies undertakings that users are really much lament to bask the comfortss provided by multimedia. In this digital universe the lightning fast sharing of digital multimedia informations has achieved the mountain extremum by agencies of omnipresent web environment. Users are ever in thirst of happening the cheapest manner to portion the media information while disregarding the opportunities of go againsting right of first publications. Consequently, the multimedia interior decorators are compelled to happen out the countermeasures to procure the multimedia contents from the interlopers. ( MIN WU and Bede Liu, 2003 ) .

Cryptography is the art and scientific discipline of pass oning in such a manner that the really being of communicating is non revealed to a 3rd party. In order to pass on without being detected, the data-hider must obey following two conditions. Perceptual restraint. The perceptual deformation between the original and stego image should non be more than a certain maximal sum, D1, for some perceptual distance step. Statistical Constraint. The implanting procedure should non modify the statistics of the host signal more than a really little figure, epsilon, for some statistical distance step. ( Ken Sullivan and Kaushal Solanki, 2005 ) . The research elicits that cryptography is nil but the multiple techniques for sharing of confidential enlightening informations, maintaining in head that the information must non be interpreted by person else who is non authorized to make so. For that one must be really peculiar about two land regulations while planing the multimedia contents. The first 1 is the perceptual restraints in which the multimedia interior decorator must be able to place the deformation between the phase image and original image and the interior decorator must maintain in head that the deformation must non transcend than the peculiar bound of the perceptual distance. Furthermore, the interior decorator must besides maintain an oculus on the statistical restraints which means that the embedded tactics should non alter the original signal in all manners. It should be modified in a really typical manner for a few statistical distance steps. ( Ken Sullivan and Kaushal Solanki, 2005 ) .

Digital sound, picture, images, and paperss are winging through internet to their several proprietors. Unfortunately, along the manner, persons may take to step in and take this content for themselves. Digital watermarking and cryptography engineering greatly reduces the cases of this by restricting or extinguishing the ability of 3rd parties to decode the content that he has taken. ( Morgan Kaufmann, 2008 ) . In the epoch of digital globalisation it can be crystal clearly understand that the multimedia elements like sound, picture, images, artworks, life, text can be shared in merely a affair of nanoseconds to the several receiver. But as said by person, every option has its pros and cons and every coin has its two sides ; The Multimedia is non an exclusion. In the few old ages the security of such communicating becomes the noticeable issues. Nevertheless, the engineering like digital watermarking and cryptography immerged and the security defects are resolved in some facets by curtailing the unauthorised parties to decode the information informations. ( Morgan Kaufmann, 2008 )

4. Research Section

As both the practical and theoretical facts studied in the above literature reappraisal we can calculate out the basic model of informations concealing in multimedia as shown in below. Here, the transmitter sends the original transcript of enlightening multimedia or original media Lashkar-e-Taiba ‘s state ( I0 ) ( It can be audio, images, artworks, picture or any signifier of multimedia elements ) ( sometimes I0 is besides normally known as covered media or host media. ) After that, the embedded faculty inserts some set of secondary informations which is besides called as embedded information ( B ) for the embedding procedure. The end product of the embedded faculty may be visually indistinguishable with the Io but it will incorporate the concealed information in it ( B ) .Generally, the end product of the embedded faculty is besides referred as pronounced media and noted by ( I1 ) . The embedded procedure introduced a new term Embedding deformation which is nil but the difference between the pronounced media ( I1 ) and the original media ( I0 ) .

Fig 1.1 Basic model of informations concealing in multimedia ( Min Wu, 2001 )

By and large, the concealed information ( B ) is nil but the aggregation of spots, which normally depends from where the application is coming. It may be encoded character twine, or from the forms or from some feasible agents or from military applications.The most indispensable factor in most of the instances is to pull out the concealed information from the pronounced media ( I1 ) in spot by spot accurate signifiers. Sometimes, the alteration of concealed informations is possible in such applications where the original media and the concealed media are partly indistinguishable like image in image or picture in picture applications. Consequently, in such applications like ownership or right of first publication protection, exact spot to seize with teeth decrypting of concealed informations from the distorted tried media is needed. Such sort of informations concealment is good known as watermarking or robust informations concealment.

A Finger printing is besides a sort of watermarking which is by and large used where assorted labels are hidden in the indistinguishable multimedia content before sharing it to more than one receiving system while these concealed labels are used to place the several receiving system.

Furthermore, the pronounced media is tested to the different assortments of processing and security onslaughts before go throughing it to the sensor faculty. After this proving procedure the information is considered as a trial media which is denoted by ( I2 ) . The difference between the tried media ( I2 ) and the pronounced media ( I1 ) is called as noise and the informations extracted from the tried media is known as extracted information which is noted as ( b^ ) .

4.1 Data concealment in Images

Basically, For the intent of informations concealing in binary images, there are two ways to modify binary images. First one is by modifying the values of each and every pel individually and another one is by altering the values of a group of pels.

In the first technique, we can merely alter the black pel of the image into white pel and white pel into black one and in the other technique we alterations such properties of images such as the thickness of the shots, their places and the comparative curvatures which normally depends on the type of image. Types of images range from text to signatures. In this 2nd attack of informations concealing in binary images merely the limited sum of enlightening informations can be hidden because of unsighted sensing ( without utilizing the original image in sensing ) and invisibleness there are really few properties in the image that can be modified for the intent of informations concealment.

On the other manus, in first attack an image is split into several blocks and for the intent of informations concealing several spots are modified in each block by altering a few pels in the several block. To do this attack crystal clear three land issues should be kept in head while utilizing this attack.

The chief issue is about choice of pels for alteration so that as possible the image should look visually natural.

Particular agencies for alteration of informations in each and every block through flappable pels.

The intent of modifying the equal figure in each block and to heighten the efficiency.

The undermentioned figure 1.2 helps to understand the construct embedding and extraction procedure.

Fig 2.1 block diagram of implanting and extraction procedure in binary images ( Min Wu, 2001 )

The above block diagram shows the measure by measure procedure of implanting and the extraction procedure of binary images for the intent of hallmark and note.

4.2 Steganography in JPEG images

Cryptography in JPEG ( joint photographic experts group ) images plays an of import function in implanting a secret information into the least important spots from the counted distinct cosine transform X and Y co-efficient. One of the demerits of this procedure is that merely few enlightening informations can be embedded into the screen image.

In this attack the secret enlightening informations can be embedded into the mid portion of the quantal DCT co-efficient frequence. This stegnographic system changes the LSBs in sequence ; accordingly, it causes deformation which is detected by steganalysis techniques. The histogram of colour frequences alterations because of embedding of high information informations. Another technique is for implanting the enlightening message spots by agencies of Pseudo random figure generator which selects DCT coefficients indiscriminately.

T-codes

T-codes belong to the household of variable length codifications. We believe that the best variable length codifications are the Huffman codes merely because they are easy to plan moreover it provides a better efficiency if the beginning statistics are identified. But still there are some restrictions for it like, when it is used in consecutive communicating normally, loss of synchronism occurs in a complex synchronism procedure and the length and the consequence are rather hard to recognize. To get the better of to this job T-codes are introduced.One of the best virtues of T-codes is that they are self-synchronising and due to that the decipherer can retrieve synchronism automatically in instance if few spots are modified or lost in a T-code encoded watercourse. In add-on, best T-codes are able to derive self-synchronisation followed by the lock loss within 1.5 characters. Therefore, t-codes replaced the Huffman codifications for the jpeg and jsted images algorithm. Furthermore, this attack is able to direct stenographic messages in lossy form which are robust in with regard to sensing or onslaught.

Implanting Algorithm for T-codes ( V.Sathya, IEEE conference )

Input signal: secret message and the screen image

Stairss:

Stepl. Encode the message utilizing the T Codes

Step2. Divide the screen image into 8×8

Blocks

Step3. Calculate DCT coefficients for

each block

Step4. Quantize the coefficients

Step5. while complete message non

embedded do

Step5.1 get following DCT coefficient

Measure 5.2 if DCT 0, DCT 1 and

DCT = -1 so

Measure 5.2.1 get following spot from

Message Fig 2.2 ( a ) Test Image

Measure 5.2.2 replace DCT LSB

with message spot

terminal { if }

terminal { While }

Step6. De-quantize and take opposite DCT

to obtain stego-image

End.

End product: Stego- image

Extracting algorithm for T-codes ( V.Sathya, IEEE conference )

Fig 2.2 ( B ) Stego image

Procedure:

Measure 1. Divide the stego image into 8×8 blocks

Step2. Calculate DCT coefficients for each block

Step3. Quantize the coefficients

Step4. while secret message non completed do

4.1 get following DCT coefficient

4.2 If DCT 0, DCT land

DCT = -1 so

Concatenate DCT LSB to

secret message

terminal { if }

terminal { while }

Step5. Decode secret message spots utilizing

the T-codes

terminal.

End product: Secret message

4.3 Data concealment in Video

In the multimedia sphere, picture plays a cardinal function of involvements among the people. A picture is nil but the proper sequence of image frames hence ; informations concealing picture techniques are correspondent in some facets of the informations concealment images techniques. One picture is considered better than 1000 words. In add-on, we can implant more enlightening information in picture as comparison to any other multimedia elements. The chief demand of picture informations concealment is by the picture suppliers like film manufacturers and News bureaus for the intent of ownership protection, entree control ( buccaneering ) , alteration sensing and fingerprinting.

The figure 3.1 below elicits the measure by measure procedure of picture informations concealment system.

Fig 3.1block diagram of proposed picture informations concealment system ( N. Murali, IEEE conference )

As the back-to-back picture frames viewed identically and each frame can be considered as a standalone unit it is easy to infix or cancel some frames or replace the places of next frames without any discernible ocular difference except in instance of fast traveling pictures and scene alterations. Though, these alterations are the most possible onslaughts in such robust informations concealing systems we can command it by infixing redundancy or seeking for frame jitter invariant field.

Furthermore, to pull off the frame jittering we introduced two schemes which are demonstrated in following fig. 3.2. Here, in first attack we a picture is divided into several sections each of which contains an indistinguishable figure of back-to-back frames and after that embed the same information in every frame of single section.

The chief advantage of this scheme is that it permits us to digest frame dropping that involves a few Numberss of detached frames. To have topmost sensing truth, redundancy plays an of import function to fight with noise from interlopers ‘ onslaughts and processing. The procedure of extraction can be accomplished by agencies of supplying more weights to the frames which are holding less deformation. Though, the first attack is capable of making all these but still it is unable to treat frame repositioning, frame inserting, or frame canceling from the larger units. To get the better of all this listed issues, the other attack has come into being which merely embeds a short version of section index in each and every frame. This information is known as frame synch which helps us to observe and turn up the frame jittering. This scheme can better the hardiness against the interloper onslaughts of frame repositioning and frame canceling through redundancy attack.

In simple footings, we use the same image informations concealing scheme to each picture frame and embed the same user information and the frame synch index in each frame of the similar sections to get the better of frame jittering.

Fig 3.2 Strategies for managing frame jittering

4.4 Data concealment in Audio

The sound cover is nil but the procedure of informations implanting in audio signals which exploits imperfectness of the human auditory system. As we know the phenomenon of sound that when the loud audio signal ( referred as masquerader ) is hearable other weak audio signal is unhearable, this depends on the temporal and spectral characteristics of both the masked signal and masquerader. The quantization noise is hidden below the cover threshold in perceptual compaction technique whereas ; in general informations concealing application the embedded signal is hidden.

Fig 4.1 Audio signal Embedding procedure

The human auditory system is designed in such a manner that it can have over a scope of power greater than one billion to one and the scope of frequences greater than one 1000 to one.

5. Decision and Recommendations

In this paper, we have studied a figure of robust methods and techniques in multimedia elements and come to the decision that among all the above techniques, informations concealment in picture has great virtues and range. Equally far as the picture informations concealment has been tested, we can conceal a big sum of informations through this attack and has been found to be used universe widely by the film manufacturers and by the intelligence bureaus in order to avoid buccaneering and to forestall ownership protection from the hackers and to direct the information to the finish in a safe mode. In this research we did n’t merely concentrate on the failing of bing informations concealing schemes but besides we have overviewed what data concealment in multimedia can make and what are the restrictions of it.

On the other manus, sound informations concealment has really limited range in future as it has restrictions of covert communicating and unaccessible information storage.