Paper 2001/062
Optimal security proofs for PSS and other signature schemes
Jean-Sébastien Coron
Abstract
The Probabilistic Signature Scheme (PSS) designed by Bellare and Rogaway is a signature scheme provably secure against chosen message attacks in the random oracle model, with a security level equivalent to RSA. In this paper, we derive a new security proof for PSS in which a much shorter random salt is used to achieve the same security level, namely we show that $\log_2 q_{sig}$ bits suffice, where $q_{sig}$ is the number of signature queries made by the attacker. When PSS is used with message recovery, a better bandwidth is obtained because longer messages can now be recovered. Moreover, we show that this size is optimal: if less than $\log_2 q_{sig}$ bits of random salt are used, PSS is still provably secure but no security proof can be tight. This result is based on a new technique which shows that other signature schemes such as the Full Domain Hash scheme and Gennaro-Halevi-Rabin's scheme have optimal security proofs.
Metadata
- Available format(s)
-
PDF PS
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- Probabilistic Signature Schemeprovable securityrandom oracle model.
- Contact author(s)
- coron @ clipper ens fr
- History
- 2001-08-13: received
- Short URL
- https://ia.cr/2001/062
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2001/062,
author = {Jean-Sébastien Coron},
title = {Optimal security proofs for {PSS} and other signature schemes},
howpublished = {Cryptology {ePrint} Archive, Paper 2001/062},
year = {2001},
url = {https://eprint.iacr.org/2001/062}
}