IACR News item: 23 June 2014
Eduarda S.V. Freire, Julia Hesse, Dennis Hofheinz
ePrint ReportOur first contribution is a formalization of NIKE protocols as ideal
functionalities in the Universal Composability (UC) framework.
As we will argue, existing NIKE definitions (all of which are game-based) do not support a modular analysis either of NIKE schemes themselves, or of the use of NIKE schemes. We provide a simple and natural UC-based NIKE definition that allows for a modular analysis both of NIKE schemes and their use in larger protocols.
We proceed to investigate the properties of our new definition, and in
particular its relation to existing game-based NIKE definitions. We find that
(a) game-based NIKE security is equivalent to UC-based NIKE security
against \\emph{static} corruptions, and
(b) UC-NIKE security against adaptive corruptions cannot be achieved
without additional assumptions (but \\emph{can} be achieved in the random oracle model).
Our results suggest that our UC-based NIKE definition is a useful and simple abstraction of non-interactive key exchange.
Additional news items may be found on the IACR news page.