Securing network traffic has always been a must requirement for any network application
that employs insecure communication channel. The reason is to provide protection for the
transmitted data over the network against unauthorized disclosure and modification of the
messages between communicating parties. Diffie-Hellman is the first published key
exchange protocol based on asymmetric techniques. The purpose of Diffie-Hellman
protocol is to enable two parties to securely exchange a session key which can then be
used for next symmetric encryption of messages. However, Diffie-Hellman itself does not
authenticate the communicating entities. In this paper, we survey on secure and efficient
key exchange protocols that are variants of Diffie-Hellman protocol. We will learn about
security and efficiency factors of key exchange protocols. We also see how different kinds
of attacks can disclose the private keys or temporary keys of recent protocols such as
one-pass and Hasan and Mohammed protocols.
The need for a key exchange protocol over insecure communication channel is raised to
prevent unauthorized access or accidental disclosure of the information while transmission
process between entities over a network. Communicating between two parties on a public
network needs to be secure to prevent any attempt from attackers to read transmitted
messages. Secure transmission means encrypting the message with an encryption key and
then sending it from one party to another. The problem is how to deliver the key between
those two parties securely. The answer is to use key exchange protocols which verify
identities of each party to another, create and distribute the key among them securely.
