2187

2. (Diffie-Hellman, 6pt) Alice and Bob have agreed on parameters (p,r) = (43897539013, 2) for the Diffie-Hellman scheme. Show a sample run of the Diffie-Hellman key agreement protocols with these parameters. Let Alice and Bob choose secret exponents a and b at random (use randrange in Python, or RandomInt(n) in Wolfram Alpha to pick a random exponent). Note: you can show the steps of the protocol graphically, as we did in class, or you can write down a transcript of what happens. In that case, preface each line by A, B, A->B, or B->A. E.g. A means Alice computes something, and A->B means Alice sends something to Bob. For example (unrelated to Diffie/Hellman):

A: computes x*a = 7*3 = 21

A->B: 21