O Sri Nagesh - Department of CSE, Sri Vasavi Engineering College, Tadepalligudem-۵۳۴۱۰۱, A.P, India,
Vankamamidi S Naresh - ۲. Department of CSE, Sri Vasavi Engineering College, Tadepalligudem-۵۳۴۱۰۱, A.P, India.

Cryptography is a well-known and well-researched topic for ages. Cryptography is the first line of defense for any networked system. By using Symmetric as well as Asymmetric Cryptography a lot of algorithms are developed. From the security point of view, Asymmetric Cryptography is more popular as security has been enhanced. RSA, DSA, ECS, DES, ECC and other algorithms have been developed for realizing Asymmetric Cryptosystem. These algorithms are primarily used for secure and reliable communication. These algorithms play a vital role in secure communication. Elliptic Curve Cryptography (ECC) provides similar security having less key size among them. In the present paper, an improved MOD-ECDH has been proposed and the proposed algorithm has been compared with other various popular algorithms like ECDH, RSA, ECS has been demonstrated. A detail both empirical and simulation study of the algorithm of ECDH and MOD-ECDH has been depicted. From result analysis, it is evident that the proposed algorithm outperforms the other algorithms in point of processing time and key size.

Elliptic Curve Diffie-Hellman algorithm (ECDH), Modified Elliptic Curve Diffie-Hellman algorithm (Mod-ECDH), Elgamal Cryptosystem (ECS), Rivert Shamir Adelman (RSA), Diffie-Hellman (DH), Voice Over Internet Protocol (VoIP).