Cryptanalysis of Loiss Stream Cipher-Revisited. (27th May 2014)

• Record Type: Journal Article
• Authors: Ding, Lin; Jin, Chenhui; Guan, Jie; Wang, Qiuyan
• Other Names: Zhdanov Renat Academic Editor.
• Is Part Of: Journal of applied mathematics. Volume 2014(2014)
• Publication Date: 2014-05-27
• Subjects: Mathematics -- Periodicals; 519.05
• DOI: 10.1155/2014/457275
• Languages: English
• ISSNs: 1110-757X

Abstract

Abstract : Loiss is a novel byte-oriented stream cipher proposed in 2011. In this paper, based on solving systems of linear equations, we propose an improved Guess and Determine attack on Loiss with a time complexity of 2 231 and a data complexity of 2 68, which reduces the time complexity of the Guess and Determine attack proposed by the designers by a factor of 2 16 . Furthermore, a related key chosen IV attack on a scaled-down version of Loiss is presented. The attack recovers the 128-bit secret key of the scaled-down Loiss with a time complexity of 2 80, requiring 2 64 chosen IV s. The related key attack is minimal in the sense that it only requires one related key. The result shows that our key recovery attack on the scaled-down Loiss is much better than an exhaustive key search in the related key setting.