## CryptoDB

### Paper: A tool for obtaining tighter security analyses of pseudorandom function based constructions, with applications to PRP to PRF conversion

Authors: Mihir Bellare R. Impagliazzo URL: http://eprint.iacr.org/1999/024 Search ePrint Search Google We present a general probabilistic lemma that can be applied to upper bound the advantage of an adversary in distinguishing between two families of functions. Our lemma reduces the task of upper bounding the advantage to that of upper bounding the ratio of two probabilities associated to the adversary, when this ratio is is viewed as a random variable. It enables us to obtain significantly tighter analyses than more conventional methods. In this paper we apply the technique to the problem of PRP to PRF conversion. We present a simple, new construction of a PRF from a PRP that makes only two invocations of the PRP and has insecurity linear in the number of queries made by the adversary. We also improve the analysis of the truncation construction.
##### BibTeX
@misc{eprint-1999-11344,
title={A tool for obtaining tighter security analyses of pseudorandom function based constructions, with applications to PRP to PRF conversion},
booktitle={IACR Eprint archive},
keywords={Pseudorandom functions, pseudorandom permutations, provable security, birthday attacks.},
url={http://eprint.iacr.org/1999/024},
note={Appeared in the THEORY OF CRYPTOGRAPHY LIBRARY and has been included in the ePrint Archive. russell@cs.ucsd.edu 10500 received December 12th, 1999.},
author={Mihir Bellare and R. Impagliazzo},
year=1999
}