Authenticated Diffie-Hellman Key Exchange Algorithm

The ability to distribute cryptographic keys has been a challenge for centuries. The Diffie-Hellman was the first practical solution to the problem .However, if the key exchange takes place in certain mathematical environments, the key exchange become vulnerable to a specific Man-inMiddle attack, first observed by Vanstone. This paper is an effort to solve a serious problem in Diffie-Hellman key exchange, that is, Man-in-Middle attack. In this paper we have used RSA algorithm along with Diffie-Hellman to solve the problem. We explore the Man-in-Middle attack, analyse the countermeasures against the attack.