Cryptology ePrint Archive: Report 2015/569

Improved (Pseudo) Preimage Attacks on Reduced-Round GOST and GrÝstl-256 and Studies on Several Truncation Patterns for AES-like Compression Functions (Full Version)

Bingke Ma and Bao Li and Ronglin Hao and Xiaoqian Li

Abstract: In this paper, we present improved preimage attacks on the reduced-round \texttt{GOST} hash function family, which serves as the new Russian hash standard, with the aid of techniques such as the rebound attack, the Meet-in-the-Middle preimage attack and the multicollisions. Firstly, the preimage attack on 5-round \texttt{GOST-256} is proposed which is the first preimage attack for \texttt{GOST-256} at the hash function level. Then we extend the (previous) attacks on 5-round \texttt{GOST-256} and 6-round \texttt{GOST-512} to 6.5 and 7.5 rounds respectively by exploiting the involution property of the \texttt{GOST} transposition operation.

Secondly, inspired by the preimage attack on \texttt{GOST-256}, we also study the impacts of four representative truncation patterns on the resistance of the Meet-in-the-Middle preimage attack against \texttt{AES}-like compression functions, and propose two stronger truncation patterns which make it more difficult to launch this type of attack. Based on our investigations, we are able to slightly improve the previous pseudo preimage attacks on reduced-round \texttt{Grøstl-256}.

Category / Keywords: secret-key cryptography / hash function, cryptanalysis, preimage, GOST, GrÝstl-256, the Meet-in-the-Middle preimage attack, truncation patterns

Original Publication (with major differences): IWSEC 2015

Date: received 9 Jun 2015

Contact author: bkma at is ac cn

Available format(s): PDF | BibTeX Citation

Note: This article is the full version of the paper published at IWSEC 2015.

Version: 20150617:151531 (All versions of this report)

Short URL: ia.cr/2015/569

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