A Combination of Hill Cipher and LSB for Image Security

Ibnu Utomo Wahyu Mulyono,Muhamad Rizky Fajar Febrian,Ajib Susanto,Ghaitsa Ardelia Rosyida

doi:10.15294/sji.v7i1.24393

Ibnu Utomo Wahyu Mulyono, Muhamad Rizky Fajar Febrian + Show 2 more

Open Access

https://doi.org/10.15294/sji.v7i1.24393

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Abstract

The maximum value obtained to test the encrypt hill cipher uses the avalanche effect with modification of one, two, three, and four key matrices 35.71%, therefore an additional security technique is needed. The Least Significant Bit (LSB) method is used to insert the ciphertext that has been generated from the hill cipher algorithm, has been testing using RGB, CMY, CMYK and YUV shapes with 6142 characters in 128 x 128 character images producing the highest PSNR value of 51.2826 dB in CMYK images. Steganography technique is applied because it has advantages in terms of imperceptibility, for example the results of a stego image are so similar to the original image that it is difficult to be distinguished by the human senses. Tests were carried out with 10 images, five images measuring 512 x 512 and five images measuring 16 x 16. While the messages to be inserted were 240, 480, and 960 characters for images measuring 512 x 512 and 24, 48 and 88 characters for images measuring 16 x16. Test results that I have done are calculated using Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR) with a minimum PSNR of 51.2907 dB which means the resulting image is quite good. Computation time is calculated using tic toc on Matlab by encrypting 2000 and 6000 characters, and also computation time.

Highlights

In its application, the internet has several impacts, for example a positive impact on everyone in finding data or information quickly and freely
Hill Cipher is a cryptographic technique that is competent and difficult to solve if it does not know the key of the matrix, but is resolved when knowing the key of the matrix, so as to cover the shortcomings of this method and to protect multiple layers of data the ciphertext insertion technique is used in the digital image of the image using the method steganography is Least Significant Bit (LSB)
From the results of research that has been done, testing that has been done with the hill cipher by using the avalanche effect only has a range of values of 8.05% to 35.71% with several different key variants, requiring additional algorithms to hide the message stronger

Summary

INTRODUCTION

The internet has several impacts, for example a positive impact on everyone in finding data or information quickly and freely. The Least Significant Bit (LSB) method uses spatial domains that are easy to manipulate and lose information. Researchers use the cryptographic method that is the Hill Cipher algorithm to produce ciphertext by encrypting a message. Hill Cipher is a cryptographic technique that is competent and difficult to solve if it does not know the key of the matrix, but is resolved when knowing the key of the matrix, so as to cover the shortcomings of this method and to protect multiple layers of data the ciphertext insertion technique is used in the digital image of the image using the method steganography is Least Significant Bit (LSB). We will describe the implementation of hiding messages or information in digital images by combining the Hill Cipher algorithm and the Least Significant Bit (LSB) method. The calculation of the time required by the system to perform a process can be used computation time in Matlab with the tic toc process

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CONCLUSION