The Ascii Code Table

Keyword(s):  
2021 ◽  
Vol 83 (1) ◽  
pp. 72-79
Author(s):  
O.A. Kan ◽  
◽  
N.A. Mazhenov ◽  
K.B. Kopbalina ◽  
G.B. Turebaeva ◽  
...  

The main problem: The article deals with the issues of hiding text information in a graphic file. A formula for hiding text information in image pixels is proposed. A steganography scheme for embedding secret text in random image pixels has been developed. Random bytes are pre-embedded in each row of pixels in the source image. As a result of the operations performed, a key image is obtained. The text codes are embedded in random bytes of pixels of a given RGB channel. To form a secret message, the characters of the ASCII code table are used. Demo encryption and decryption programs have been developed in the Python 3.5.2 programming language. A graphic file is used as the decryption key. Purpose: To develop an algorithm for embedding text information in random pixels of an image. Methods: Among the methods of hiding information in graphic images, the LSB method of hiding information is widely used, in which the lower bits in the image bytes responsible for color encoding are replaced by the bits of the secret message. Analysis of methods of hiding information in graphic files and modeling of algorithms showed an increase in the level of protection of hidden information from detection. Results and their significance: Using the proposed steganography scheme and the algorithm for embedding bytes of a secret message in a graphic file, protection against detection of hidden information is significantly increased. The advantage of this steganography scheme is that for decryption, a key image is used, in which random bytes are pre-embedded. In addition, the entire pixel bits of the container image are used to display the color shades. It can also be noted that the developed steganography scheme allows not only to transmit secret information, but also to add digital fingerprints or hidden tags to the image.


2020 ◽  
Vol 20 (1) ◽  
pp. 15
Author(s):  
Dwi Rahmasari Kinasih Gusti ◽  
Kiswara Agung Santoso ◽  
Ahmad Kamsyakawuni

Cryptography is knowledge of encoding messages by observe to security aspects. Cryptography uses two types of keys, namely symmetric keys and asymmetric keys. Vigenere cipher is a technique to encrypt messages by symmetric key. Vigenere cipher can be combined by several patterns and ASCII code. The pattern used can vary as long as the text can be returned to original message (can be decrypted). On this paper, we will modified plaintext before encrypt using vigenere cipher. The way to modified the plaintext are flip and shift rows of bit. The effect of the algorithm changes can be seen based on the renewal value obtained. If the correlation value gets smaller, it means the algorithm is better. The results of this study is the correlation value using vigenere cipher with modified plaintext is better compared to vigenere cipher with original plaintext. Keywords: ASCII, Patterned, Bits, Vigenere Cipher


The growth rate of the Internet is exceeding that of any previous technology. As the Internet has become the major medium for transferring sensitive information, the security of the transferred message has now become the utmost priority. To ensure the security of the transmitted data, Image steganography has emerged out as an eminent tool of information hiding. The frequency of availability of image file is high and provides high capacity. In this paper, a method of secure data hiding in image is proposed that uses knight tour positions and further 8-queen positions in 8*8 pixel blocks.The cover image is divided into 8*8 pixel blocks and pixels are selected from each block corresponding to the positions of Knight in 8*8 chessboard starting from different pixel positions. 8-pixel values are selected from alternate knight position. Selected pixels values converted to 8-bit ASCII code and result in 8* 8 bit matrix. 8-Queen’s solution on 8*8 chessboard is applied on 8*8 bit matrix. The bits selected from 8-Queens positions and compared with 8-bit ASCII code of message characters. The proposed algorithm changes the LSB of only some of the pixels based on the above comparison. Based on parameters like PSNR and MSE the efficiency of the method is checked after implementation. Then the comparison done with some already proposed techniques. This is how, image steganography showed interesting and promising results when compared with other techniques.


2012 ◽  
Vol 6 (4) ◽  
pp. 55-70 ◽  
Author(s):  
Sunil Kumar Muttoo ◽  
Vinay Kumar ◽  
Abhishek Bansal

The 8-queens problem of placing 8 non-attacking queens on an 8x8 chessboard is used to hide message in an image. The method helps in randomizing the bit selection in a cover image for hiding purpose. Cover image is divided into blocks of 8x1 bytes and then masked with solutions of the 8-queens problem. Bits from the block are collected corresponding to the 8-queen solution to make a 7 bit string. LSB of the block is not considered. It gives a number in the range of 0 to 127. If a bit string, corresponding to the 8-queens solutions, matches with ASCII code of the first character from message, the corresponding solution number of the 8-queens problem is encrypted using RC4, and the cipher is stored in first block of the cover. This encrypted value works as key. The solution number corresponding to next character is XORED with the key and the resultant value is embedded in the LSB of next block. The algorithm has been tested with cover of different image file formats like BMP, PNG and TIFF. The algorithm provides very good capacity, imperceptibility and robustness.


Sign in / Sign up

Export Citation Format

Share Document