ABSTRACT
Imagine for a moment that people have the perfect cryptography system, completely impenetrable and totally unreadable by anyone who intercepts an encrypted message that they send. This is called the Key Exchange Problem and, in the past, couriers often used a diplomatic pouch system to solve it. Keys would then be distributed and the agents would go out into the field. The problem is that these methods are expensive and time consuming, and they require a lot of planning. In 1976, Whitfield Diffie and Martin Hellman proposed a key exchange method that can be done publicly but nevertheless maintains the secrecy of the key. The idea behind the Diffie–Hellman Key Exchange can be used to solve this problem, enabling one person to do the coin flip and have the other be certain that it's being done fairly.
