A fast Diffie-Hellman protocol in genus 2

In this paper it is shown how the multiplication by M map on the Kummer surface of a curve of genus 2 defined over F-q can be used to construct a Diffie-Hellman protocol. We show that this map can be computed using only additions and multiplications in F-q. In particular we do not use any divisions, polynomial arithmetic, or square root functions in F-q, hence this may be easier to implement than multiplication by M on the Jacobian. In addition we show that using the Kummer surface does not lead to any loss in security.