Cryptology ePrint Archive: Report 2011/323

A New Related-Key Boomerang Distinguishing Attack of Reduced-Round Threefish-256

Shusheng Liu and Libin Wang and Zheng Gong

Abstract: On Nov 2007, NIST announced the SHA-3 competition to select a new hash standard as a replacement of SHA-2. On Dec 2010, five submissions have been selected as the final round candidates, including Skein, which have components based on ARX. In this paper, a new related-key boomerang distinguishing attack is proposed on 31-round Threefish-256 with a time complexity of about $2^{234}$. Our improved attack is based on the efficient algorithms for calculating differentials of modular addition.

Category / Keywords: Skein, Differential analysis, Related key, Boomerang attack

Date: received 16 Jun 2011, last revised 20 Nov 2011

Contact author: cis gong at gmail com

Available format(s): PDF | BibTeX Citation

Note: Updated version

Version: 20111120:130120 (All versions of this report)

Short URL: ia.cr/2011/323