PENERAPAN ENKRIPSI ELGAMAL DAN STEGANOGRAFI LSB ACAK UNTUK MENGURANGI KETERDETEKSIAN PESAN PADA CITRA DIGITAL

Abstract

The rapid exchange of digital information raises concerns about data security and privacy. Sending sensitive messages directly through open networks makes them vulnerable to interception. To overcome this problem, a combination of cryptography and steganography is proposed. Cryptography secures the message content, while steganography hides the message's existence. This study aims to implement the ElGamal algorithm for asymmetric encryption and the Random Least Significant Bit (LSB) method for embedding the ciphertext into digital images. The Random LSB method is chosen to scatter bits non-sequentially, making the message harder to detect compared to sequential LSB. The results of this research demonstrate that the system successfully encrypts messages­­ and embeds them into images with a high imperceptibility rate. The testing using Peak Signal-to-Noise Ratio (PSNR) resulted in an average value above 50 dB, indicating that the stego-image quality remains very close to the original image and is difficult to distinguish visually.