ISSN: 2229371X
Ramveer Singh^{*1}, Sanjive Tyagi ^{2}, Awakash Mishra^{3} and Deo Brat Ojha^{4}

Corresponding Author: Ramveer Singh, Email: [email protected] 
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The scenario of present day of information security system includes confidentiality, authenticity, integrity, nonrepudiation. This present paper focus is enlightening the technique to secure data or message with authenticity and integrity. We kept in mind the security of transmission and capacity of channel, triple EHDES provides more complexity and enhanced security and compression with sequitur provides reduce size data or image for efficiency of communication channel. Author’s previous articles define the strength of EHDES based on variation of key, cascading of EHDES or triple EHDES makes this approach more effective and usable.
Keywords 
Double  EHDES, Cryptography, Stegnography, Compression, Image File. 
INTRODUCTION 
Steganalysis is a technology which determines the presence of a hidden message or image in cover image and attempt to disclose the actual contents of this message [1].A more erudite method of steganography is by merging the two techniques to produce more security to secure data transmission such that if intruders detect the presence of data even then message cannot be decode without the knowledge of key. The most common stegno method is the LSB approach, or Least Significant Bit. As we know digital pixels are represented by three colors: red, green and blue. These colors together form digital pictures or video. Each color of every pixel requires 1 byte or 8 bits of information. Since the first bit is the “least significant” or carries the least amount of importance in the byte, this steganographic technique chooses to overwrite the first bit of successive bytes until the entire secret message is embedded into the original source file, or the cover data. Since we have only modified the least significant bits of a portion of the source file, the human eye should not be able to detect the degradation in the picture or video [2]. 
PRELIMINARIES 
Stegnography 
Steganography is a technique used to embed secret information into nonsecret information, preventing the message from being detected by nonauthorized people. [3] The purpose of steganography is to hide the very presence of communication by embedding messages into innocuouslooking cover objects, such as digital images. To accommodate a secret message, the original cover image is slightly modified by the embedding algorithm to obtain the stego image. The embedding process usually incorporates a secret stegokey that governs the embedding process and it is also needed for the extraction of the hidden message [4]. There are three basic views behind hiding information. The first is capacity, which is the amount of information that can be embedded within the cover file. An informationhiding algorithm has to be able to compactly store a message within a file. Next is security, which refers to how a thirdparty can detect hidden information within a file. Intuitively, if a message is to be hidden, an ideal algorithm would store information in a way that was very hard to notice. High security layers have been proposed through three layers to make it difficult to break through the encryption of the input data and confuse steganalysis too. Various encryption techniques like cryptography, digital watermarking, steganography etc have already been introduced in attempt to address these growing concerns [5]. Steganography have four application areas: Copyright Protection. It has security, invisibility and robustness requirements. Watermark techniques fit in this area. Authentication. It has security and invisibility requirements. Digital signature fits in this area. Secret and Invisible Communication. It has requirements for security, invisibility and insertion of high volumes of secret data. [6] 
CRYPTOGRAPHY 
Cryptography is a branch of applied mathematics that aims to add security in the ciphers of any kind of messages. Cryptography algorithms use encryption keys, which are the elements that turn a general encryption algorithm into a specific method of encryption. The data integrity aims to verify the validity of data contained in a given document. [7] 
DEFINITION 
A cryptosystem is a five tuple (M, C, K, E, D), where the following conditions are satisfied: 
1. M is a finite set of possible plain texts. 
2. C is a finite set of possible ciphertexts. 
3. K, the keyspace, is a finite set of possible keys. 
4. For each K k, there is an encryption rule eK E. and a corresponding decryption rule dK D. Each eK : M C and dK : C M are functions such that dK(eK(x)) = x for every plaintext x M. The main property is property 4. It says that if a plaintext x is encrypted using eK, and the resulting ciphertext is subsequently decrypted using dK, then the original plaintext x results. 
TRIPLE EHDES 
Triple EHDES uses the cascading or chain of Enhanced Data Encryption Standard (EHDES) [7, 8]. Let EK (P.T.) and DK (P.T.) represent the EHDES encryption and decryption of P.T. using EHDES key K respectively. Each EHDES encryption/decryption operation is a compound operation of EHDES encryption and decryption operations. The following operations are used: 
1) EHDES encryption operation: 
the transformation of a 64bit block P.T. into a 64bit block C.T. that is defined as follows: 
C.T = EK3 (DK2(EK1(P.T.))). 
2) EHDES decryption operation: 
the transformation of a 64bit block P.T into a 64bit block C.T. that is defined as follows: C.T. = DK1 (EK2 (DK3 (P.T.))). 
The standard specifies the following keying options for bundle (K1, K2, K3) 
1) Keying Option 1: K1, K2 and K3 are independent keys. 
2) Keying Option 2: K1 and K2 are independent keys and K3 = K1. 
3) Keying Option 3: K1 = K2 = K3. 
DATA COMPRESSION 
A compression scheme can be employed what is known as lossless compression on secrete message to increase the amount of hiding secrete data, a scheme that allows the software to exactly reconstruct the original message [10]. The transmission of numerical images often needs an important number of bits. This number is again more consequent when it concerns medical images. If we want to transmit these images by network, reducing the image size is important. The goal of the compression is to decrease this initial weight. This reduction strongly depends of the used compression method, as well as of the intrinsic nature of the image. Therefore the problem is the following: 1. To compress without lossy, but with low factor compression. If you want to transmit only one image, it is satisfactory. But in the medical area these are often sequences that the doctor waits to emit a diagnostic. 2. To compress with losses with the risk to lose information. The question that puts then is what the relevant information is’s to preserve and those that can be neglected without altering the quality of the diagnosis or the analysis. The human visual system is one of the means of appreciation, although subjective and being able to vary from an individual to another. However, this system is still important to judge the possible causes of degradation and the quality of the compression [11]. 
The SEQUITUR Algorithm [12] 
The SEQUITUR algorithm represents a finite sequence as a context free grammar whose language is the singleton set {s}. It reads symbols onebyone from the input sequence and restructures the rules of the grammar to maintain the following invariants: (A) No pair of adjacent symbols appear more than once in the grammar, and (B) Every rule (except the rule defining the start symbol) is used more than once. To intuitively understand the algorithm, we briefly describe how it works on a sequence 123123. As usual, we use capital letters to denote nonterminal symbols. After reading the first four symbols of the sequence 123123, the grammar consists of the single production rule S 1, 2, 3, 1 where S is the start symbol. On reading the fifth symbol, it becomes S 1, 2, 3, 1, 2 Since the adjacent symbols 1, 2 appear twice in this rule (violating the first invariant), SEQUITUR introduces a nonterminal A to get 
S A, 3,A A 1, 2 Note that here the rule defining nonterminal A is used twice. Finally, on reading the last symbol of the sequence 123123 the above grammar becomes S A, 3, A, 3 A 1, 2 This grammar needs to be restructured since the symbols A, 3 appear twice. SEQUITUR introduces another nonterminal to solve the problem. We get the rules 
S B,B B A 3 A 1 2 However, now the rule defining nonterminal A is used only once. So, this rule is eliminated to produce the final result. S B, B B 1, 2, 3 Note that the above grammar accepts only the sequence 123123. 
Our Approach 
In our new concept, we encrypt the original text message letter by letter applying a function, which involves certain mathematical operation using corresponding letters and also numbers from the original image, then we use highly secure encryption using Double  EHDES algorithm to encrypt the message. For encryption we need to use secret key for plain text M and Triple  EHDES encryption function. Cipher Text: C = EK(EHDES)(Message). Then using sequitur compression algorithm on secrete data file (c) to hide a large amount of data with high security. Then Hide compressed and encrypted text into cover image using Stegnography algorithm i.e List Significant Bit (LSB) coding is the way to embed information in cover image file. In this LSB technique is applied on compressed encrypted message. It is really appreciable method to provide high security to the high confidential image. The proposed method is enhanced or characterized by robustness, larger amount of secrete data, less time complexity and especially high security. Proposed work deals with the security of text message by applying symmetric key cryptography algorithm Triple  EHDES in which we use generated secret key which are calculated using Triple  EHDES key generation process. Secret key is used at both sender side and receiver side. Secret key are always different using Triple  EHDES algorithm with modification that a mathematical function F. This function using a value depends on the decimal value of the R array of each pixel of cover image. The first letter corresponding to the first pixel and next to the second pixel and so on . A mathematical function F is using R array of each pixel of cover image and initial key K for generating the Secret key Knew i. The encrypted code is taken digit by digit. This approach constitutes the phase one security in our work. Now in the second phase of work, we have used Sequitur loss less compression technique to compress the encrypted text so that we can hide large amount of data in cover image. In next phase, we have introduced the hiding of encrypted and compressed text file into any cover image. In our work secret key are always different because we are generating randomly number based on the confidential message text and original cover image. This method is a unique to generate random number such that no one can guess the random number to crack the secret key. 
A. Algorithm for encrypting the confidential message 
Step 1: 
Convert the text to number system, which are ASCII number of character. 
Step 2: 
A mathematical function f is used which gives the number of random numbers below given number say R. Step 3: Here, the value of R depends on the decimal value of character of cipher text. 
Step 4: 
The F function is then applied on the random number R by checking the parity of decimal value of character of cipher text. X =ASCII Converted Character numbers of confidential Message. R =Decimal value of the R array of the pixels the original cover image. Knew i = F(R) = Result value after applying the F function 
Step 5: 
Now using random number R, generate secret key 
Calculate, Knew i = F(R and K) 
Where R is a random number. 
Step 6: 
Encryption using secret key and Tripe EHDES 
Plain Text M 
Cipher Text: C = EK(EHDES)(X). 
B. Algorithm for compress the confidential message 
Step: 
Perform the lossless compression technique (sequitur) on cipher text to increase the amount of hiding secrete data. 
Process for convert cover image file 
Step 1: Generating blocks 
Phase 3: Quantization 
Quantization is the step where the most of the compression takes place. DCT really does not compress the image, as it is almost lossless. Quantization makes use of the fact that, the high frequency components are less important than the low frequency components. The Quantization output is 
The Z(u,v) matrix could be anything, but the JPEG committee suggests some matrices which work well with image compression. 
Phase 4: Compression using SEQUITUR 
After quantization, the scheme uses a filter to pass only the string of nonzero coefficients. By the end of this process we will have a list of nonzero tokens for each block preceded by their count. DCT based image compression using blocks of size 8x8 is considered. After this, the quantization of DCT coefficients of image blocks is carried out. The SEQUITER compression is then applied to the quantized DCT coefficients. 
C. Algorithm to embed confidential message into cover image file. 
Algorithm to embed confidential message into cover image file named inFile generate new file with embedded message file named outFile. EncodedMessage (msg,inFile on inputmode, outFile on outputmode) 
Step 1: 
Read offset bytes from input inFile and writes to output File outFile 
Step 2: 
Calculate message length and write it into output file by embedding using XOR function it in last two bits for every byte. Suppose, Message length being 16 bits, will be stored in 8 pairs of 2 bits. 
Step 3: 
Embed each byte of message in 4 pairs of 2 bits each is embedded in 4 byte of input file and written into output file named outFile. 
Step 4: 
Write the remaining bytes of the input file into output file. 
D. Algorithm for generate of message from Image 
The picture is received at receive side. This function decode message from a file named outFile open on output mode. Decode Message (outFile on Inputmode) 
Step 1: 
Read offset bytes from the input file and apply again XOR function, Generate message bit. 
Step 2: 
Read last 2 bits of consecutive 8 bytes and concatenate them to get the message length. 
Step 3: 
Read last 2 bits from input file in pairs of 4 and concatenate them to get message of 1 byte. 
Step 4: 
Repeat step 3 until the message is extracted of calculated length. 
Step 5: 
Decompress & Decrypt the message. 
CONCLUSIONS 
In this paper, we propose an appropriate scheme by using the LSB matching method to embed secure data into the stegnoimage. Stegnography is a technique to embed a message and Triple  EHDES is to provide high level security. Data compression using sequitur provide us a effective and maximum channel utilization. Triple – EHDES is the three times cascading of EHDES with different mode. 
References 
