密码学报2016，Vol.3Issue(3)：282-291,10.DOI:10.13868/j.cnki.jcr.000128
PRIDE算法密钥扩展算法的研究*
An Improvement of the Key Schedule of PRIDE
摘要
Abstract
The lightweight block cipher PRIDE was designed by Albrecht et al., and presented at CRYPTO 2014. The designers claimed that the construction of linear layers has good security and efficiency. Slide attack is an important method of cryptanalysis on block ciphers, which applies the self-similarity of the encryption function and key schedule to analyze the block cipher. In this paper, by studying the key schedule of PRIDE, we consider the slide attack on PRIDE. Firstly, we found that the round subkeys are not periodic, so that the single-key slide attack on PRIDE does not work. Furthermore, a discussion of the non-linear functionsgr(i) is given, and the related keys used for related-key slide attack are found. Then, based on the related keys, the related-key slide attacks on PRIDE without whitening-key and full PRIDE are presented. Both of the attacks require 233plaintexts, and the time complexity is 260.7 and 2124.7 encryptions, respectively. Due to the weakness of key schedule, an improved design of key schedule is proposed, which is, an improvement of the non-linear functionsgr(i). With the improved key schedule, the single-key and related-key slide attack do not work anymore. The results show that the key schedule plays an important role on the security of the block cipher and the good design of key schedule is also important.关键词
分组密码/PRIDE算法/密钥扩展算法/滑动攻击Key words
block cipher/PRIDE/key schedule/slide attack分类
信息技术与安全科学引用本文复制引用
戴艺滨,陈少真..PRIDE算法密钥扩展算法的研究*[J].密码学报,2016,3(3):282-291,10.基金项目
信息保障技术重点实验室开放基金项目(KJ-13-010) （KJ-13-010）
