هبة هلال هادي السلامي

Digital image protection is crucial since images often contain private and sensitive information in business, medical, and military. One of the best techniques for securing the content of these images is encryption. This work introduces a cryptosystem known as Elliptic Curve Diffie-Hellman Hill Cipher (ECDHHC) that uses the modified Elliptic Curve Diffie-Hellman (ECDH) key exchange protocol to generate the shared secret key integrated with the Hill Cipher (HC). With this combination, the correlation between adjacent pixels in the ciphered image is effectively removed, and the level of unpredictability and uncertainty for ciphered image is also enhanced. The suggested approach used the key space, entropy, histogram, anti-noise attack, differential attack, and correlation coefficient to evaluate the performance of the encryption method. According to simulation findings, the proposed method offers a high level of security, and efficiency, and resists attackers.

Several advancements have been made to the Massey-Omura cryptographic system due to its significance in secure communication. These improvements aim to improve security and efficiency, ensuring the system remains robust against evolving technological challenges in data exchange. This paper presents a modification of the elliptic curve analogue of the Massey-Omura cryptosystem by incorporating a matrix-based structure. Compared to the original system, this novel approach offers enhanced security, as an attacker must solve the Elliptic Curve Discrete Logarithm Problem (ECDLP) multiple times, depending on the size of the secret matrices chosen by the users. This significantly strengthens the system’s resilience against cryptanalysis and increases its potential for use in modern secure communication protocols

Various techniques were used to improve and propose cryptographic systems based on elliptic curves. In particular, the Diffie-Hellman key exchange protocol is widely used in most of these systems. In this work, we introduce an efficient approach based on the block matrices integrated with elliptic curves to increase the security of this protocol. With the new system, we can reduce key size without expanding the underlying elliptic curve. Therefore, the proposed protocol security will be more intractable since it will need to solve the Elliptic Curve Discrete Logarithm Problem more than once based on the chosen block matrices compared with the original protocol.