Paper 2009/572

On the Equivalence of Two Models for Key-Dependent-Message Encryption

Alexander W. Dent

Abstract

In this paper we examine the relationship between the security models for key-dependent-message encryption proposed by Backes \emph{et al.} \cite{Backes:08:OAEP} and Camenisch \emph{et al.} \cite{Camenisch:09:Public}. We show that when the two notions are equivalent for certain logical classes of function families when the number of keys $\ell$ in the system is logarithmically small.

Note: The proof in this paper contains a flaw which we cannot currently overcome. Hence, we are withdrawing the paper until we can provide a full proof.