OPTIMASI VALIDASI UJI PRIMA MILLER–RABIN PADA PEMBANGKITAN KUNCI ALGORITMA ELGAMAL PADA KEAMANAN CITRA

Abstract

Digital image security is an important aspect of modern information systems, especially in the storage and transmission of multimedia data. One widely used approach is public key cryptography, such as the ElGamal algorithm. ElGamal security is highly dependent on the selection of large prime numbers in the key generation process. Therefore, an efficient and accurate primality testing method is needed. This study proposes an optimization of the Miller–Rabin primality test validation in ElGamal algorithm key generation to improve the efficiency and security of image encryption. The optimization is performed by determining the optimal number of iterations and combining it with an initial deterministic test. The test results show that this optimization is able to speed up key generation time without reducing the level of security, and produces good image encryption quality based on histogram analysis and pixel correlation values.