Hybrid Algorithm Combining Modified Diffie Hellman and RSA

The Classic Diffie-Hellman (CDH) algorithm encounters several security problems. The algorithm security depends on the complexity of solving the discrete logarithm and the integer factorization problem. The security also depends on the length of bits keys used. In this paper, we proposed a hybrid algorithm, the combination of Modified Diffie Hellman (MDH) with the Rivest, Shamir, and Adelman (RSA) algorithm. The MDH will not use primitive root (g). Instead, it will use two prime numbers (P and Q) for key exchange. It reduces the possibility of a man-in-the-middle attack. Furthermore, the MDH has an authentication mechanism. If both shared keys are equal, the communication will continue. Otherwise, it will stop because it is compromised. Also, the RSA algorithm will use the two prime numbers generated by MDH (P and Q). The RSA algorithm will perform the encryption and decryption message. The Diffie Hellman (DH) and the RSA Algorithms are the basis of several security standards and services on the internet, especially TLS and SSL. If the security of both algorithms is compromised, such systems will collapse. In this proposal, the combined cryptography system aims to achieve secret message exchange; it uses random prime numbers after multiplication and eventually shared with the other end of a communication. The proposed algorithm secretly generate a value so that the security level increases.