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PROPOSED DATA HIDING TECHNIQUE TEXT IMAGE INSIDE IMAGE (TIII)
1Hebah H. O. Nasereddin& 2 Murad Saleh Al Farzaeai
1Middle East University, Amman, Jordan, P.O. Box: 144378, Code 11814 Amman-Jordan.
2AmmanArab University for Graduate Studies, Email: 1[email protected] , 2[email protected]
ABSTRACT
Information hiding techniques have recently become important in a number of application areas, there are many techniques to achieve hiding data, and hiding text inside image is one field of them. The paper gives short example of these techniques and proposes a new technique to hide text inside digital image by the concept of the visual representation of the text within image.
Keywords: Hiding data, Steganography, visual representation of text, cover image, stego image.
1. INTRODUCTION
In the world Data hiding science is entirely separated from the science of data encryption cryptography. It is called Steganography. "Famous examples of steganography go back to antiquity. According to a story from Herodotus, a slave’s head was shaved by his master, Histiæus, and tattooed with a secret message around 440 B.C. After growing the hair back, the message disappeared and then the slave journeyed to carry the message. When he shaved his head upon arriving, the message was revealed [9]. In 1860, the major problems had been solved to make a small image by
"Darjun", who is a French photographer worked in the war Frank and France in 1870- 1861 when Paris was besieged, by writing messages on photographic films which were sent by the carrier pigeon. The purpose of this was to invoke disobedience against his antagonist Persinas. Steganography, is the ability of hiding data in redundant bits of any cover media. Its Target is to keep the secret information unreadable without damaging the cover media environment. “Steganography replaces unneeded bits in image, sound, andtext files with secret data. Instead of protecting data the wayencryption does, steganography hides the very existence of the data.” [6]. "The internet and the world wide web have revolutionized the way in which digital data is distributed"[3].The Number of spies is increasing year after year and now its time to hit the target to defense a secret message during transmission.
There are several inclusion conventions and techniques that enable us to hide information in a specific object.
All these conventions and techniques should achieve a number of requirements in order to be able to apply data hiding theory correctly. The following are some main requirements:
1. The correct completion the hidden information when including it inside the carrier cover, so that the confidential message should not be changed in any way in case of adding information or changing any included information after it has been hidden. Changing the included data means the failure of the process.
2. The carrier medium that covers the confidential message should not be changed also, or at least its changes are not visible to unaided eye. In case these changes are large and visible, the person who watches will know that there is hidden information within the message and so will try to open or damage it.
3. Concerning the water marks, changes that happened to the message should not affect the strength of the water mark. Some treatments that may affect the water mark are the functions of zooming in, zooming out, cutting, pasting, and rotating images.
4. Always taken into consideration that the attacker knows the existence of hidden information within the carrier cover.
184 SOME DATA HIDING WAYS:
1. Cryptography which refers to encode data with some algorithms and send it to receiver that the only one has a key to decryption.
2. Steganography which hides data into a cover media so that it becomes invisible, Steganography knowledge has a multiple ways to hide a data. "Steganography is the process of hiding one medium of communication (text, sound or image) within another. The word Steganography comes from the Greek steganos (covered or secret) and graphy (writing or drawing) and means, literally, covered writing."[2].
3. Watermarking is a branch of information hiding which is used to hide proprietary information in digital media like photographs, digital music, or digital video. The ease with which digital content can be exchanged over the Internet has created copyright infringement issues. Copyrighted material can be easily exchanged over peer-to- peer networks, and this has caused major concerns to those content providers who produce these digital contents. This paper provides a survey of techniques to watermark data files like text, images,audio and video [1].
2. DATA HIDING TECHNIQUES.
Hiding Data in Images
Hiding a secret message in images is the most popular data hiding technique that using Steganography encode.
For example, suppose one can hide a message in three pixels of an image (24-bit colors) suppose the original 3 pixels are:
(00100111 11101001 11001000) (00100111 11001000 11101001) (11001000 00100111 11101001)
A steganographic program could hide the letter "A" which has a position 65 into ASCII character set and have a binary representation "01000001", by altering the blue channel bits of pixels.
(01000001 11101001 11001000) (00100111 11001000 11101000) (11001000 00100111 11101001) [10].
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Hiding Data in Text
This technique is studying the morphology of languages characters first.
both Arabic and English languages have points in their letters, the amount of pointed letters differ too much. English language has points in only two letters, small "i" and small "j", while Arabic has in 15 letters out of its 28 alphabet letters as shown in Fig. 1. This large number of points in Arabic letters made the points in any given Arabic text remarkable and can be utilized for steganography and information security as presented by Shirali-Shahreza in their “new approach to Persian/Arabic text steganography”[6].
"Steganography example of securing: 110010 in the Arabic text, illustrated earlier, are readjusted assuming the extensions added are before the letters. To add more security and misleading to trespassers, both options of adding extensions before and after the letters can be used within the same document but in different paragraphs or lines. For example: the even lines or paragraphs use Steganography of extensions after the letters and the odd use extensions before or visa versa [6].
The literature is quite limited in relation to reversible data hiding for 3D models. Some methods have been proposed by Cayre and Macq , by Wang and Cheng , and by Wang and Wang .Because these all use similar methods to achieve reversibility, we present here only one example of reversible data hiding scheme. After that, we survey some data hiding and watermarking schemes of 3D models in the spatial domain and in the transform domain [7].
Hiding Data in Mp3 files
Steganography is based on the fact that manufacture files that contain redundant information like image or audio file to be compressed.
MP3Stego will hide information in MP3 files during the compression process. The data is first compressed, encrypted and then hidden in the MP3 bit stream. The hiding process takes place at the heart of the Layer III encoding process namely in the inner_loop. The inner loop quantizes the input data and increases the quantizer step size until the quantized data can be coded with the available number of bits. Another loop checks that the distortions introduced by the quantization do not exceed the threshold defined by the psychoacoustic model. The part2_3_length variable contains the number of main data bits used for scalefactors and Huffman code data in the MP3 bit stream. We encode the bits as its parity by changing the end loop condition of the inner loop. Only randomly chosen part2_3_length values are modified; the selection is done using a pseudo random bit generator based on SHA-1 [4].
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3. HIDING TEXT IMAGE INSIDE IMAGE (TIII) TECHNIQUE 3.1 TIII METHODOLOGY
When we write a Message in black on a white page, we're actually drawing characters Message on the white paper, and after analyzing the message, we find that this Message consists of two main components, the first component is the black lines that indicate the Characters and the second component is a white paper that represents the background that helps to distinguish the black characters, and when we check deep we can fragment both components to small particles (dots) united in a shape and different in color, the first component, the black lines, consisting of a black dots and the second component, a white background consists of white-set of dots, These dots in a logical order, so as to make the brain distinguishes the message, and this is what we call a visual representation of the message or letters. The technique which we call the shortcut (TIII), trying to take advantage of this visual representation in the process to hide a specific message within an image.
The technique (TIII ) deals with a text as an image (TEXT IMAGE) which will be hidden inside another image (COVER IMAGE) to generate an image have the same details of the (COVER IMAGE) but also have the hidden (TEXT IMAGE) inside it and will be called (STEGO IMAGE). So :
TEXT IMAGE is an image consist of two colors black and white ,which has the message that will be hidden. This image consist of black and white pixels ,which represent the visual representation of hidden message, in figure (1,a) we have an image(7×7) consist of white and black pixels in a logical order to represent the capital character ( M ), the black pixels represent the visual view of the capital character (M) .
Figure (1,a)
This visual representation of the characters in the image and the constraint of colors give TIII ability to represent the two colors by tow numbers ( 0 ,1) and convert the image of the black and white pixels to image of zeros and ones as we see in the figure (1,b), And TIII will call it by TEXT IMAGE or (M1):
If M1(x,y) ==' black' then M1(x,y)=0;
Else M1(x,y)=1;
Figure (1,b) TEXT IMAGE (M1) 1 1 1 1 1 1 1
1 0 1 1 1 0 1
1 0 0 1 0 0 1
1 0 1 0 1 0 1
1 0 1 1 1 0 1
1 0 1 1 1 0 1
1 1 1 1 1 1 1
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Now to hide this TEXT IMAGE of numbers (TIII) bring a digital image(COVER IMAGE) which has the same size like the TEXT IMAGE . figure (2,a) represent an image(7×7) which her pixels have the values between (0 and 255 ) and represent the(COVER IMAGE) or (M2). TIII will modified (COVER IMAGE) to be able to generate the (STEGO IMAGE), The modifications will be in the values of the pixels of the COVER IMAGE as the following:
If M2(x,y)==255 then M2(x,y)=254;
Figure (2,a) M2
figure (2,b) shows the modification that happened in the pixels values over (254), And this modification is necessary to avoid generating any pixels have values over than 255 and to keep them in the range of the gray scale of the images which is (0 -> 255).
Figure (2,b) M2 After modification
The STEGO IMAGE (NEW1) is the generating image which has the appearance of the cover image and has the hidden text inside it ,and it will be exactly twice bigger than the COVER IMAGE (M2) because in front of each pixel in the COVER IMAGE (M2) TIII will generate two pixels:
The first pixel of NEW1 will equal to the corresponding pixel in the cover image with respect of the increasing of the position as it shown in the figure(3,a ) and by the role
NEW1(x,(y*2)-1)== N2(x,y);
255 255 255 255 255 255 255
255 80 65 55 70 254 255
255 59 99 230 255 33 255
255 88 99 80 180 100 255
255 68 90 99 100 80 255
255 59 99 230 60 33 255
255 255 255 255 255 255 255
254 254 254 254 254 254 254
254 80 65 55 70 254 254
254 59 99 230 254 33 254
254 88 99 80 180 100 254
254 68 90 99 100 80 254
254 59 99 230 60 33 254
254 254 254 254 254 254 254
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To generate the value of the second pixel of NEW1 TIII take the value of the first pixel of cover image M2 plus the value of the first pixel at the text image M1 with respect of the increasing of the position as it shown in the figure( 3,b ) and by the role :
NEW1(x,y*2)== N2(x,y)+ N1(x,y);
189 Figure (b,3) 3-2:TIII Terminology:
TEXT IMAGE M1 : refers to the hidden text but in the form of image.
COVER IMAGE M2 :refers to the image which will be used as carrier of the hiding image.
STEGO IMAGE NEW1: refers to the image which already has hiding text inside it.
X : refers to the vertical coordinate of the images (rows).
Y: refers to the horizontal coordinate of the images(columns) 3-3:Real Example for TIII:
Using the MATLAB (version 7) we build tow functions ,the first for hiding and we will call it HIDFUN, it will receive two image inputs M1(text image) and M2(cover image) and it will return one image output NEW2 (cover image with hidden text image).The second function for extract the hidden text image, and we will call it OPENFUN, it will receive one image input NEW1, and it will return one image output NEW2 (the hidden text image).
254 254 254 254 254 254 254
254 80 65 55 70 254 254
254 59 99 230 254 33 254
254 88 99 80 180 100 254
254 68 90 99 100 80 254
254 59 99 230 60 33 254
254 254 254 254 254 254 254
255 254 255 254 255 254 255 254 255 254 255 254 255 254
255 254 80 80 66 65 56 55 71 70 69 69 255 254
255 254 59 59 99 99 231 230 254 254 33 33 255 254
255 254 88 88 100 99 80 80 181 180 100 100 255 254
255 254 68 68 91 90 100 99 101 100 80 80 255 254
255 254 59 59 100 99 231 230 61 60 33 33 255 254
255 254 255 254 255 254 255 254 255 254 255 254 255 254
1 1 1 1 1 1 1
1 0 1 1 1 0 1
1 0 0 1 0 0 1
1 0 1 0 1 0 1
1 0 1 1 1 0 1
1 0 1 1 1 0 1
1 1 1 1 1 1 1
TEXT IMAGE M1
STEGO IMAGE NEW1
COVER IMAGE M2
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In the HIDFUN function we will write this code:
For i=1:1:1754 for j=1:1:1240 u= ( j * 2 );
if M1 ( i, j) <=128 % (1) for x=1:1:3
if M2 ( i, j,x) ==255 then M2 ( i, j,x) ==254;% (2) NEW1 ( i, u-1 , x ) = M2 ( i , j , x);% (3)
NEW1 (i , u , x ) = M2 ( i , j , x ) + 1 ;%(4) end
else
for x=1:1:3
if M2 ( i, j,x) ==255 then M2 (i,j,x) ==254; % (2) NEW1 (i , u-1 , x ) = M2 ( i , j , x);% (3)
NEW1 ( i , u , x ) = M2 ( i , j , x);% (4) end
end end end
this function already make the modification in the pixels values of COVER IMAGE (M2),and also detect the tow colors (white and black) in the TEXT IMAGE (M1) and generating the pixels of the STIGO IMAGE (NEW1) as:
(1) Point where the function determine the white and black pixels in (M1).
(2) Point where the function make the modification on the pixels of (M2).
(3) Point where the function generate the first pixel of (NEW1) . (4) Point where the function generate the second pixel of (NEW1) .
M2.jpg (1754 * 1240 * 3)
191
M1.jpg (1754 * 1240 * 3)
NEW1.jpg (1754 * 2480 * 3)
192
At the second function OPENFUN, TIII generate the TEXT IMAGE (NEW2) depending on the different between the first pixels value and the second pixel value of the STEGO IMAGE (NEW1), and it will have the following code inside it:
for i=1:1:1754 for j=2:2:2480 u=( j / 2);
for x=1:1:3
NEW2 ( i, u , x ) = NEW1 ( i, j , x ) - NEW1 ( i, j-1 , x );
end
end
end
NEW1.jpg (1754 * 2480 * 3)
193 4. CONCOLUSION
This paper addresses the problem of data hiding . We propose a new data hiding technique dealing with the visual representation of the text as an image and hide it in another image. This proposed technique (TIII) has some limitations, limitation of TIII comes in the following points:
TIII assumes that the text you want to hide is already exists on an image which has constraint in colors ( white and black ) .TIII assumes that the cover image comes to matching the text image in the dimensions and size.
The proposed technique TIII did not addressed the different of the size between the cover image and the stego image ,because it can be solve by using cover images whit the same size of the stego image and doing some resizing methods to the cover image to make it at the same size of the text image.
The font size of the message in the text image will be an important factor in the integrity of the message during the transmission pross and the size of the hidden message , so that when the font size be large the safety of the transmission will be strong ,but the size of the message will small and vice versa.
5. REFERENCES
[1]L.Robert, and T.Shanmugapriya," A Study on Digital Watermarking Techniques", International Journal of Recent Trends in Engineering, Vol. 1, No. 2, May 2009,Page 1.
[2] Babita Ahuja and Manpreet Kaur Manav Rachna College of Engineering, Deptt. Of CS, Faridabad, India,
"High Capacity Filter Based Steganography ", International Journal of Recent Trends in Engineering, Vol. 1, No. 1, May 2009, Page 1.
[3] Jong Jin Chae, "Robust Techniques for Hiding Data in Images and Video", UMI Microform 9997425 ,March 2000, Page 1.
[4] Mark Noto, "MP3Stego: Hiding Text in MP3 Files", SANS Institute 2001, Page 5.
[5] Xinghao Jiang and Tanfeng Sun, Bin Chen, Rongjie Li, Bing Feng1 , "A Novel Video Content Understanding Scheme Based on Feature Combination Strategy ", JOURNAL OF COMPUTERS, VOL. 4, NO. 7, JULY 2009 , Page 1.
[6] Adnan Abdul-Aziz Gutub and Manal Mohammad Fattani , "A Novel Arabic Text Steganography Method Using Letter Points and Extensions ", SANS Institute 2001, Page 3.
[7]PENG-CHENG WANG AND CHUNG-MING WANG "Reversible Data Hiding for Point-Sampled Geometry", JOURNAL OF INFORMATION SCIENCE AND ENGINEERING 23, 1889-1900 (2007), Page 2.
[8] Jithendra K. Paruchuri, Sen-ching S. Cheung and Michael W. Hail,” Video Data Hiding for managing Privacy Information in Surveillance Systems”, DRAFT, August 20, 2009,Page 5.
[9] AYHANYILMAZ,” ROBUST VIDEO TRANSMISSION USING DATA HIDING”, SEPTEMBER 2003.
[10] Amanpreet Kaur and Renu Dhir, and Geeta Sikka,” A New Image Steganography Based On First Component Alteration Technique”, (IJCSIS) International Journal of Computer Science and Information Security,Vol. 6, No. 3, 2009
