Rancang Bangun Algoritma ChaCha20-Poly1305 Berbasis SHA-256 Untuk Pengamanan Dokumen Penting Masyarakat

Abstract

Data security is a critical aspect in protecting sensitive information, especially in digital environments where data is vulnerable to unauthorized access. This study aims to implement the ChaCha20-Poly1305 algorithm with a SHA-256-based key for data protection, as well as to evaluate its performance and security through several testing scenarios. The method involves implementing the ChaCha20-Poly1305 algorithm using keys generated from SHA-256 hashing, followed by testing using parameters such as Avalanche Effect, image visual analysis, MSE, PSNR, and performance comparison with the AES-256-GCM algorithm. The results show that the system successfully restores data with 100% similarity after decryption. The Avalanche Effect achieves an average value of 50.038%, indicating high sensitivity to key changes. Additionally, entropy increases from 0.7159 to 7.9993 and pixel correlation decreases from 0.7914 to -0.0085, indicating a high level of randomness in the encrypted data. The MSE value of 16,715.31 and PSNR value of 6.19 dB indicate significant differences between original and encrypted data. Based on these results, it can be concluded that the ChaCha20-Poly1305 algorithm with a SHA-256 key is capable of securing data with a high level of randomness while maintaining data integrity after the decryption process.