## Cryptology ePrint Archive: Report 2009/147

Preimage Attack on ARIRANG

Deukjo Hong and Woo-Hwan Kim and Bonwook Koo

Abstract: The hash function ARIRANG is one of the 1st round SHA-3 candidates. In this paper, we present preimage attacks on ARIRANG with step-reduced compression functions. We consider two step-reduced variants of the compression function. First one uses the same feedforward$_1$ as the original algorithm, and the other one has the feedforward$_1$ working at the output of the half steps. Our attack finds a preimage of the 33-step OFF(Original FeedForward$_1$)-variants of ARIRANG-256 and ARIRANG-512 from Step 1 to Step 33, and a preimage of the 31-step MFF(Middle FeedForward$_1$)-variants of ARIRANG-256 and ARIRANG-512 from Step 3 to Step 33.

Category / Keywords: hash function, preimage attack, SHA-3, ARIRANG

Date: received 30 Mar 2009, last revised 30 Mar 2009

Contact author: hongdj at ensec re kr

Available format(s): PDF | BibTeX Citation

Short URL: ia.cr/2009/147

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