Section 74 - 7.5

I don't see the point of the beta requirements for the Decisional Diffie Hellman Problem. Also I get the feeling that Diffie Hellman and Discrete Log should be equivalent but I guess since there is no proof then it could be so otherwise too. The DDH <=> El Gamal and CDH <=> El Gamal proofs are pretty nice, they remind be of a lot of Comp Sci proofs from my algorithms class.