Paper 2007/158
A Simple Security Analysis of Hash-CBC and a New Efficient One-Key Online Cipher
Mridul Nandi
Abstract
In Crypto 2001, Bellare {\em et al.} introduced {\em online cipher} (or online permutation) and proposed two Hash-CBC mode constructions, namely {\bf HCBC} and {\bf HPCBC} along with security proofs. We observe that, the security proofs in their paper are {\em wrong} and it may not be fixed easily. In this paper, we provide a {\em simple} security analysis of these online ciphers. Moreover, we propose two variants of HPCBC, namely {\bf MHCBC-1} and {\bf MHCBC-2}. The first variant, MHCBC-1, is a slight modification of HPCBC so that it is more efficient in performance as well as in memory compare to HPCBC. The other one, MHCBC-2 requires only {\em one-key} (note that, HCBC and HPCBC require at least two and three keys respectively) and does not require any $\varepsilon$-$\mathrm{\Delta}$Universal Hash Family (which is costly in general).
Metadata
- Available format(s)
-
PDF
PS
- Category
- Secret-key cryptography
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- random permutationpseudo random permutationOnline functionOnline permutationHash-CBC.
- Contact author(s)
- mridul nandi @ gmail com
- History
- 2007-05-07: revised
- 2007-05-07: received
- See all versions
- Short URL
- https://ia.cr/2007/158
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2007/158,
author = {Mridul Nandi},
title = {A Simple Security Analysis of Hash-{CBC} and a New Efficient One-Key Online Cipher},
howpublished = {Cryptology {ePrint} Archive, Paper 2007/158},
year = {2007},
url = {https://eprint.iacr.org/2007/158}
}
