Designing Advanced Cryptographic Solutions for Cloud Storage Security Through Dual-Layer Encryption Protocols

Abstract

This paper presents a novel hybrid cryptosystem combining ElGamal and ChaCha20-Poly1305 for securing data in cloud storage environments. Elgamal, an asymmetric encryption algorithm is utilized for secure key exchange to ensure the safe transmission of keys. ChaCha20-Poly1305, a high-performance symmetric encryption algorithm is used for efficient data encryption and authentication, thereby addressing the performance limitations of using traditional asymmetric algorithms alone. Using ChaCha20-Poly1305 for bulk data encryption and transmission significantly improves speed and reduces computational overhead compared to using only asymmetric algorithm. This makes it ideal for modern cloud storage applications. This novel system is made to provide robust defence against common cloud-based attacks such as eavesdropping, replay attacks, brute force and man-in-the-middle attacks. By making use of the strengths of both asymmetric and symmetric encryption algorithms, the system will ensure high security with better performance. The proposed hybrid Algorithm was tested and compared with the traditional Elgamal alone, and it achieved 83% faster encryption, 79.5% faster decryption and 69.5% lower memory usage. This shows its efficiency for secure cloud data storage and transmission.