Diffie-Hellman Implemented

• The simplest implementation of the protocol uses two integers, a modulus, and a primitive root of the modulus.

• This is how it works.
  • Sender and recipient agree on a finite cyclic group of numbers, called G and a generating element g in G.
    • g is assumed to be known by everyone, including attackers.
  • The sender picks a random natural number a and sends g^a to the recipeint.
  • The recipient picks a random natural number b and sends g^b to the sender.
  • The sender computes (g^b)^a.
  • The recipient computes (g^a)^b.
  • Both sender and recipient are now in possession of the group element g^ab which can serve as the shared secret key.
    • This works because (g^b)^a equals (g^a)^b.

Is there a Diffie-Hellman example?

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© 2006 John Michael Pierobon

Notes