One of the known cryptographic protocols today is the Diffie-Hellman key exchange (D-H). Diffie-Helman key exchange has other terms that may be used interchangeably with the former and these are: Diffie-Hellman key establishment, Diffie-Hellman key agreement, Diffie-Hellman handshake, Exponential key exchange, Diffie-Hellman protocol, and Diffie-Hellman key negotiation.
This is a key agreement that permits the transfer of a key between two groups for the purpose of a symmetric key encryption while inhibiting the direct conduction of a key value. A mathematical process is also secretly utilized on a key so as to keep it concealed.
It is a protocol that permits the creation of shared secret key between two parties that have not a single idea about each other. With the use of a D-H, setting up of a shared secret key becomes possible even within an unprotected communications channel. Another use of this type of a key exchange is that it may be utilized in the encryption of the succeeding communications while utilizing a symmetric key cipher.
Malcolm J Wiliamson
This cryptographic protocol was based on the original idea of Martin Hellman and Whitfield Diffie during the early days of the year 1976. But then, it was discovered few years after that the project was formulated a little earlier by Malcolm J. Williamson, a member of the signals intelligence agency in UK, GCHQ. In addition, the invention was kept as a confidential algorithm subsequent to its completion.
And, in the year 2002, Hellman proposed the scheme of calling this algorithm as the Diffie-Hellman-Merkle exchange of the key. This change of name is their way of acknowledging the great efforts of Ralph Merkle on the creation of this public-key cryptography.
Looking closely into this type of algorithm, one can recognize easily that Diffie-Hellman key agreement is actually a non-authenticated key exchange protocol. In addition, it is a type of protocol that gives basis for different genuine protocols. It is also employed in offering a perfect forward secrecy in the Transport Layer Security’s transient forms.