Paper 2004/102
The Exact Security of an Identity Based Signature and its Applications
Benoît Libert and Jean-Jacques Quisquater
Abstract
This paper first positively answers the previously open question of whether it was possible to obtain an optimal security reduction for an identity based signature (IBS) under a reasonable computational assumption. We revisit the Sakai-Ogishi-Kasahara IBS that was recently proven secure by Bellare, Namprempre and Neven through a general framework applying to a large family of schemes. We show that their modified SOK-IBS scheme can be viewed as a one-level instantiation of Gentry and Silverberg's alternative hierarchical IBS the exact security of which was never considered before. We also show that this signature is as secure as the one-more Diffie-Hellman problem. As an application, we propose a modification of Boyen's "Swiss Army Knife" identity based signature encryption (IBSE) that presents better security reductions and satisfies the same strong security requirements with a similar efficiency.
Metadata
- Available format(s)
-
PDF
PS
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- ID-based cryptographysignaturesprovable securityexact security
- Contact author(s)
- libert @ dice ucl ac be
- History
- 2004-05-24: last of 13 revisions
- 2004-05-07: received
- See all versions
- Short URL
- https://ia.cr/2004/102
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2004/102,
author = {Benoît Libert and Jean-Jacques Quisquater},
title = {The Exact Security of an Identity Based Signature and its Applications},
howpublished = {Cryptology {ePrint} Archive, Paper 2004/102},
year = {2004},
url = {https://eprint.iacr.org/2004/102}
}
