Implementasi Kriptografi Hybrid Algoritma Elgamal Dan Double Playfair Cipher Dalam Pengamanan File Jpeg Berbasis Dekstop

Abstract

Digital image is a representative of the image taken by the machine with a form of approach based on sampling and quantization. Sampling states the size of the boxes arranged in rows and columns. In other words, sampling on the image states the size of the pixels (dots) in the image, and quantization states the value of the brightness level expressed in grayscale values ??according to the number of binary bits used by the machine, in other words quantization in the image represents the number of colors in the image. It is very important in securing digital images from parties who do not have access rights is very important. If important information in the form of digital images falls into the wrong hands, it will cause unwanted things, for example image manipulation in a negative form and can harm the owner of the image. In solving this problem, the author uses the ElGamal method which is used to maintain the security of the data by calculating the discrete logarithm of a group of prime integers in which the multiplication operation is carried out and combining it with the Double Playfair Cipher method to encode the image encryption and the ElGamal Algorithm to encrypt the key. from Double Playfair Cipher. The image is first encrypted using the Double Playfair Cipher Algorithm, then the Double Playfair key is encrypted using the ElGamal Algorithm. The result of testing the designed application is the formation of a public key and a private key which is carried out in encrypting and decrypting an image file so that the exchange of information in the form of digital images can be carried out safely.