Enhanced Hill Cipher Encryption Using Chaotic Logistic Maps for Improved Security and Key Randomness

In cryptography, maintaining data confidentiality and ensuring resilience against various attacks are of utmost significance. A popular classical encryption method that is well-known for its effectiveness and simplicity in protecting text data is the Hill cipher. The Hill Cipher algorithm is improved as a polygraphic substitution cipher based on linear algebra. This algorithm uses a square matrix key, and its key matrix must be invertible. However, its susceptibility to known-plaintext and chosen-plaintext attacks, along with key matrix constraints, limits its effectiveness. This paper presents an enhanced Hill cipher algorithm that integrates chaotic logistic maps to improve security, key randomness, and resistance to cryptanalytic attacks. Using the unpredictable nature of chaotic sequences, a dynamic key matrix is generated, ensuring stronger diffusion and confusion properties in encryption. The proposed method eliminates weaknesses associated with traditional hill cipher and enhances resistance to statistical and brute-force attacks. The results of experiments and analysis of security show that the chaotic logistic Hill cipher significantly improves the encryption strength. This approach provides a robust and adaptable cryptographic solution for securing textual data in modern applications.