Unconditionally secure information authentication in presence of erasures

Abstract

The traditional authentication model assumes that the data loss on the communication channel between the sender and the receiver is handled by mechanisms that should be studied separately. In this paper, we consider a more general setting where both unconditionally secure information authentication and loss-resilience are achieved at the same time via erasure-tolerant authentication codes (or η-codes), and we address some fundamental questions concerning erasure-tolerant authentication codes. Namely, we adapt several lower bounds on the probability of successful deception derived for the traditional authentication model to the setting that we consider here. We also analyze the distance properties of the η-codes and the security properties of the η-codes constructed by means of concatenation and composition. One interesting class of η-codes is the class of η-codes with minimal probabilities of successful impersonation and substitution. We show that all members of this class can be represented as a composition of an authentication code with minimal impersonation and substitution probabilities and an erasure-resilient code. Finally, we present some examples of η-code constructions. © Springer-Verlag Berlin Heidelberg 2005.