Paper Info
Title
Non Observability in the Random Oracle Model
Abstract
Security proofs in the Random Oracle Model (ROM) often make use of the fact that the queries made by the adversary to the oracle are observable as well as the responses to those queries can be programmed. While, the issue of programmability of query responses has received attention in the literature, to the best of our knowledge, observability of the adversary's queries has not been identified as an artificial artefact of the Random Oracle Model. In this work, we propose a variant of ROM, in which the challenger of the security game cannot \"observe\" the adversary's queries to the random oracle, but can (possibly) continue to \"program\" the query responses. We show that this model is separable from ROM by proving that Fischlin's online extractors from [Fis05]) cannot exist when they are Non Observing. At the same time, we also show that reductions/extractors that seem to rely on observability, can sometimes achieve the same effect by programming of the responses. We also show that the schemes RSA-PFDH and Schnorr signatures are still secure with Non Observing reductions.
Year
DOI
Venue
2012
10.1007/978-3-642-41227-1_5
ProvSec
DocType
Volume
ISSN
Journal
2012
0302-9743
Citations 
PageRank 
References 
7
0.48
21
Authors
2
Name
Order
Citations
PageRank
Prabhanjan Ananth123418.43
Raghav Bhaskar21919.88