Andrey Sidorenko (Eindhoven): Efficient pseudorandom generators based on the DDH assumption

A family of pseudorandom generators based on the decisional Diffie-Hellman (DDH) assumption is proposed. The new construction is a modified and generalized version of the Dual Elliptic Curve generator proposed by Barker and Kelsey. Although the original Dual Elliptic Curve generator is shown to be insecure, the modified version is provably secure and very efficient compared to many other pseudorandom generators based on discrete log assumptions.

Our generator can be based on any group of prime order provided that an additional requirement is met (i.e., there exists an efficiently computable function that in some sense enumerates the elements of the group). Two specific instances are presented. The techniques used to design the instances, for example, the new probabilistic randomness extractor are of independent interest for other applications.