Regresar

Analysis of the Application of Steganography Applied in the Field of Cybersecurity

Abstract:

The image files have data areas that are not very important for the visualization of the corresponding image and, if these areas are changed or altered, the image does not have a perceptible visual change, therefore they can be used to hide information, having almost certainty that the image has not been altered. The least significant bit (LSB) method consists in replacing the last bit of each byte and can do it in several bytes at the same time and the image will not have a noticeable change. Each substituted bit is part of a letter of the message that you want to hide in the given image. In general, images with PGM extension are very useful to apply the technique (LSB) since they are images whose content is given without following some algorithm of compression; This means that the content of the file is more readable and easy to work since it is in the ascci format (US standard code for information exchange). The content of an image with PGM extension, can be visualized using a simple text editor, so that the ASCII information can be seen as a representation of whole numbers, the value of these numbers will represent the intensity of color, 255 is white and 0 is black. If each row of the matrix represents an image data and every last digit, which is the least significant bit, is altered, then the eight bits corresponding to each altered byte would represent a letter belonging to a hidden message word. If this sequence is repeated several times you can hide more information such as phrases or sentences. Steganography is a useful tool in the field of computer security where it is required to verify that private information is correctly used by the user determined using the encryption in the personal key. There are already several software products that are responsible for carrying out this process, one of these cases is OpenStego, which encrypts the information using steganography and through passwords ensures that only the bearer of it will be able to visualize said information. We will show that the use of the Fortran, MatLab programming language presents great advantages for steganography since access to memory spaces through pointers allows freeing up memory at runtime, which provides a high degree of efficiency in the execution of a Program. Fortran, being a programming language oriented to mathematical calculation in general, has tools that facilitate its application and expressly the matrix calculation used in steganography.