Hybrid Cryptosystem for Data Security Using ZKP, AES-256-GCM, and LSB-Based Steganography

Abstract

Modern digital communication requires stronger mechanisms for both confidentiality and authentication to mitigate threats such as impersonation, replay, and eavesdropping. Although traditional cryptographic methods offer secrecy, they lack strong identity verification in adversarial environments. To ensure security in both transmission and authentication, we proposed a hybrid framework combining the most effective mechanisms for secure communication, enhanced with LSB Steganography to conceal sensitive information. Zero-knowledge proofs are used for secure authentication. Diffie-Hellman with AES-256-GCM ensures confidentiality and data integrity, while LSB Steganography provides secure concealment of transmitted communication. Our method has been evaluated using a variety of techniques, including steganographic quality assessment, encryption-decryption performance testing, and authentication time measurement, confirming its resilience against common security risks. The proposed methods achieve PSNR values up to$\mathbf{7 4. 5 8 ~ d B}$and SSIM of 0.9999. The encryption time ranges from 0.035 ms to 0.068 ms, while the decryption time remains consistently lower, ranging from 0.008 ms to 0.015 ms. The results demonstrate that the proposed framework is a viable option for secure data transfer, as it guarantees confidentiality, integrity, authentication, and covert communication.