Pengamanan Data Text Menggunakan Algoritma Vigenere Cipher Berdasarkan Logistic Map Chaos

Abstract

Data security in text communication is an important issue in the digital era. The Vigenere cipher is a classical cryptographic method, but it is vulnerable to cryptanalysis due to its repeating key pattern. This study aims to enhance the security of the Vigenere cipher by modifying its key using a chaos-based Logistic Map. The proposed method generates a pseudo-random key from the Logistic Map and applies it to the Vigenere encryption process, using modulo 64 to support Base64 characters. The security performance is evaluated using the Character Change Rate (CCR) metric. The results show that the modified method produces a more random and complex ciphertext compared to the standard Vigenere cipher. The CCR analysis indicates greater sensitivity and improved resistance to pattern-based attacks. In conclusion, integrating the Logistic Map into the Vigenere cipher effectively enhances text data security and provides a stronger encryption scheme.