Delpech de Saint Guilhem, Cyprien ; Fischlin, Marc ; Warinschi, Bogdan (2020)
Authentication in Key-Exchange: Definitions, Relations and Composition.
33rd IEEE Computer Security Foundations Symposium. virtual Conference (22.-26.06.2020)
doi: 10.1109/CSF49147.2020.00028
Konferenzveröffentlichung, Bibliographie

Kurzbeschreibung (Abstract)

We present a systematic approach to define and study authentication notions in authenticated key-exchange protocols. We propose and use a flexible and expressive predicate-based definitional framework. Our definitions capture key and entity authentication, in both implicit and explicit variants, as well as key and entity confirmation, for authenticated key-exchange protocols. In particular, we capture critical notions in the authentication space such as key-compromise impersonation resistance and security against unknown key-share attacks. We first discuss these definitions within the Bellare-Rogaway model and then extend them to Canetti-Krawczyk-style models. We then show two useful applications of our framework. First, we look at the authentication guarantees of three representative protocols to draw several useful lessons for protocol design. The core technical contribution of this paper is then to formally establish that composition of secure implicitly authenticated key-exchange with subsequent confirmation protocols yields explicit authentication guarantees. Without a formal separation of implicit and explicit authentication from secrecy, a proof of this folklore result could not have been established.

Frage zum Eintrag

Redaktionelle Details anzeigen