Paper 2014/441
Improved Generic Attacks Against Hash-based MACs and HAIFA
Itai Dinur and Gaëtan Leurent
Abstract
The security of HMAC (and more general hash-based MACs) against state-recovery and universal forgery attacks was very recently shown to be suboptimal, following a series of surprising results by Leurent \emph{et al.} and Peyrin \emph{et al.}. These results have shown that such powerful attacks require much less than $2^{\ell}$ computations, contradicting the common belief (where $\ell$ denotes the internal state size). In this work, we revisit and extend these results, with a focus on properties of concrete hash functions such as a limited message length, and special iteration modes. We begin by devising the first state-recovery attack on HMAC with a HAIFA hash function (using a block counter in every compression function call), with complexity $2^{4\ell/5}$. Then, we describe improved trade-offs between the message length and the complexity of a state-recovery attack on HMAC. Consequently, we obtain improved attacks on several HMAC constructions used in practice, in which the hash functions limit the maximal message length (e.g., SHA-1 and SHA-2). Finally, we present the first universal forgery attacks, which can be applied with short message queries to the MAC oracle. In particular, we devise the first universal forgery attacks applicable to SHA-1 and SHA-2.
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- A major revision of an IACR publication in CRYPTO 2014
- Keywords
- Hash functionsMACHMACMerkle-DamgårdHAIFAstate-recovery attackuniversal forgery attackGostStreebogSHA family.
- Contact author(s)
- gaetan leurent @ normalesup org
- History
- 2014-06-14: revised
- 2014-06-13: received
- See all versions
- Short URL
- https://ia.cr/2014/441
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2014/441, author = {Itai Dinur and Gaëtan Leurent}, title = {Improved Generic Attacks Against Hash-based {MACs} and {HAIFA}}, howpublished = {Cryptology {ePrint} Archive, Paper 2014/441}, year = {2014}, url = {https://eprint.iacr.org/2014/441} }