Steganography Using Substitution Principle

In this chapter, the author describes the various substitution-based image steganography techniques. Basically, there are four categories of substitution techniques: (1) least significant bit (LSB) substitution, (2) LSB array-based substitution, (3) group of bits substitution (GBS), and (4) adaptive LSB substitution. The LSB substitution-based techniques are very much insecure (detectable by RS analysis), so LSB array, GBS, and adaptive LSB substitution techniques are proposed in literature. If substitution principle is used in a steganography technique, then it must be evaluated by RS analysis.

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Gandharba Swain

The combination of pixel value differencing (PVD) and least significant bit (LSB) substitution gives higher capacity and lesser distortion. However, there are three issues to be taken into account: (i) fall off boundary problem (FOBP), (ii) pixel difference histogram (PDH) analysis, and (iii) RS analysis. This paper proposes a steganography technique in two variants using combination of modified LSB substitution and PVD by taking care of these three issues. The first variant operates on 2 × 3 pixel blocks and the second technique operates on 3 × 3 pixel blocks. In one of the pixels of a block, embedding is performed using modified LSB substitution. Based on the new value of this pixel, difference values with other neighboring pixels are calculated. Using these differences, PVD approach is applied. The edges in multiple directions are exploited, so PDH analysis cannot detect this steganography. The LSB substitution is performed in only one pixel of the block, so RS analysis also cannot detect this steganography. To address the FOBP, suitable equations are used during embedding procedure. The experimental results such as bit rate and distortion measure are satisfactory.


Author(s):  
Meenakshi S Arya ◽  
Meenu Rani ◽  
Charndeep Singh Bedi

<p>With the intrusion of internet into the lives of every household and terabytes of data being transmitted over the internet on daily basis, the protection of content being transmitted over the internet has become an extremely serious concern. Various measures and methods are being researched and devised everyday to ensure content protection of digital media. To address this issue of content protection, this paper proposes an RGB image steganography based on sixteen-pixel differencing with n-bit Least Significant Bit (LSB) substitution. The proposed technique provides higher embedding capacity without sacrificing the imperceptibility of the host data. The image is divided into 4×4 non overlapping blocks and in each block the average difference value is calculated. Based on this value the block is classified to fall into one of four levels such as, lower, lower-middle, higher-middle and higher. If block belongs to lower level then 2-bit LSB substitution is used in it. Similarly, for lower-middle, higher-middle and higher level blocks 3, 4, and 5 bit LSB substitution is used. In our proposed method there is no need of pixel value readjustment for minimizing distortion. The experimental results show that stego-images are imperceptible and have huge hiding capacity.</p>


Author(s):  
Meenakshi S Arya ◽  
Meenu Rani ◽  
Charndeep Singh Bedi

<p>With the intrusion of internet into the lives of every household and terabytes of data being transmitted over the internet on daily basis, the protection of content being transmitted over the internet has become an extremely serious concern. Various measures and methods are being researched and devised everyday to ensure content protection of digital media. To address this issue of content protection, this paper proposes an RGB image steganography based on sixteen-pixel differencing with n-bit Least Significant Bit (LSB) substitution. The proposed technique provides higher embedding capacity without sacrificing the imperceptibility of the host data. The image is divided into 4×4 non overlapping blocks and in each block the average difference value is calculated. Based on this value the block is classified to fall into one of four levels such as, lower, lower-middle, higher-middle and higher. If block belongs to lower level then 2-bit LSB substitution is used in it. Similarly, for lower-middle, higher-middle and higher level blocks 3, 4, and 5 bit LSB substitution is used. In our proposed method there is no need of pixel value readjustment for minimizing distortion. The experimental results show that stego-images are imperceptible and have huge hiding capacity.</p>


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gandharba Swain

The least significant bit (LSB) substitution techniques are detected by RS analysis and the traditional pixel value differencing (PVD) approaches are detected by pixel difference histogram (PDH) analysis. The PVD steganography can escape from PDH analysis by using the edges in multiple directions. This paper proposes a steganography technique by exploiting the edges in eight directions and also using LSB substitution to resist from both RS analysis and PDH analysis. For every 3×3 pixel block the central pixel is embedded with 3 or 4 bits of data by modified LSB substitution technique. Then this new value of the central pixel is utilized to calculate eight difference values with eight neighboring pixels. These eight difference values are used to hide the data. There are two types with regard to two different range tables. Type 1 uses 3 bit modified LSB substitution and range table 1. Type 2 uses 4 bit modified LSB substitution and range table 2. Type 1 and type 2 are also known as variant 1 and variant 2, respectively. Type 1 possesses higher PSNR and type 2 possesses higher hiding capacity.


2019 ◽  
Vol 7 (4) ◽  
pp. 254
Author(s):  
Nada E. Tawfiq

Image files can hide text without their size being affected too much. This process called steganography which allows hiding text in images without any suspicions from intruders. This paper addresses an improved LSB substitution algorithm for hiding Kurdish text information written in text file into digital image as steganography technique. The algorithm consists of two main phases, the first phase holds the encryption of the Kurdish text message and the embedded technique while the second phase hold the message extraction followed by decryption to get the original code of each character. The algorithm contains many procedures to enhance this process. Least Significant Bit method is used to hide the Kurdish text, in order to keep the features and characteristics of the original image. Applying the proposed approach shows that it seems work in a best case by hiding and retrieving text from the digital image which is used as a carrier of this text. Delphi 2010 was used to simulate both encrypt-embedded phase and extract-decrypt phase, and the results were obtained with high and security which proved the efficiency of the algorithm, where the hidden Kurdish text didn’t make any distortion or change over the cover image.


Author(s):  
M. Miftakul Amin

<p>ABSTRAK <br /> <br />Keamanan dalam menyampaikan pesan rahasia merupakan faktor penting dalam penyebaran informasi di dunia maya. Melindungi supaya pesan yang akan dikirimkan sampai kepada pihak yang berhak, perlu dibuat sebuah mekanisme penyembunyian pesan. Tujuan dari penelitian ini adalah menyembunyikan pesan berupa teks rahasia ke dalam citra digital true colour 24 bit dalam format RGB. Metode yang digunakan untuk menyisipkan pesan rahasia menggunakan metode LSB (Least Significant Bit) dengan mengganti bit terakhir atau bit ke-8 dalam setiap komponen warna RGB. <br />Pilihan jenis file citra RGB dengan pertimbangan kapasitas pesan yang dapat disisipkan lebih besar dibandingkan jika menggunakan citra grayscale, hal ini dikarenakan dalam 1 pixel dapat disisipkan 3 buah bit pesan. Ujicoba yang dilakukan memberikan hasil bahwa pesan yang disembunyikan ke dalam citra digital tidak mengurangi kualitas citra digital secara signifikan, dan pesan yang telah <br />disembunyikan dapat diekstrak kembali, sehingga pesan yang dikirimkan dapat sampai dengan aman kepada penerima.</p>


2014 ◽  
Vol 8 (1) ◽  
pp. 19-37 ◽  
Author(s):  
Mamta Juneja

With the more and more advancement in technology, internet has become the most important medium for all kinds of confidential as well as non-confidential communications. Security is the major issue for such communications and steganography is most widely accepted tool for information security. An effort has been made in the present paper to propose a secured model for communication using image steganography. It presents two components based LSB steganography method, adaptive LSB based steganography method for embedding data in high and low transition parts of an image respectively. Hybrid edge detection filter is proposed to divide an image in low and high transition areas. AES (Advanced Encryption Standard) and Randomization is incorporated to provide two-tier security. Comparison analysis of output results with other existing techniques on basis of capacity, imperceptibility is giving the proposed approach an edge over others. The proposed approach has been thoroughly tested for various steganalysis attacks like visual analysis, histogram analysis, chi-square, and RS analysis and could sustain all these attacks very well.


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