《计算机应用》唯一官方网站 ›› 2022, Vol. 42 ›› Issue (9): 2742-2749.DOI: 10.11772/j.issn.1001-9081.2021071340

• 网络空间安全 • 上一篇    

基于差分表的Blow-CAST-Fish算法的密钥恢复攻击

孙晓玲(), 李姗姗, 杨光, 杨秋格   

  1. 防灾科技学院 信息工程学院,河北 三河 065201
  • 收稿日期:2021-07-27 修回日期:2021-09-27 接受日期:2021-10-13 发布日期:2021-11-01 出版日期:2022-09-10
  • 通讯作者: 孙晓玲
  • 作者简介:李姗姗(1981—),女,河南洛阳人,副教授,博士,主要研究方向:大规模地球科学计算;
    杨光(1985—),女,吉林洮南人,副教授,博士,主要研究方向:数据分析、图像处理;
    杨秋格(1981—),女,山东聊城人,讲师,硕士,主要研究方向:数据分析。
  • 基金资助:
    国家自然科学基金资助项目(42007422);中央高校基本科研业务费专项(ZY20215152);廊坊市科技局科学研究与发展计划项目(2020011024)

Blow-CAST-Fish key recovery attack based on differential tables

Xiaoling SUN(), Shanshan LI, Guang YANG, Qiuge YANG   

  1. School of Information Engineering,Institute of Disaster Prevention,Sanhe Hebei 065201,China
  • Received:2021-07-27 Revised:2021-09-27 Accepted:2021-10-13 Online:2021-11-01 Published:2022-09-10
  • Contact: Xiaoling SUN
  • About author:LI Shanshan, born in 1981, Ph. D., associate professor. Her research interests include large-scale geoscience computing.
    YANG Guang, born in 1985, Ph. D., associate professor. Her research interests include data analysis, image processing.
    YANG Qiuge, born in 1981, M. S., lecturer. Her research interests include data analysis.
  • Supported by:
    National Natural Science Foundation of China(42007422);Fundamental Research Funds for Central Universities(ZY20215152);Scientific Research and Development Program of Langfang Science and Technology Bureau(2020011024)

摘要:

针对Blow-CAST-Fish算法攻击轮数有限和复杂度高等问题,提出一种基于差分表的Blow-CAST-Fish算法的密钥恢复攻击。首先,对S盒的碰撞性进行分析,分别基于两个S盒和单个S盒的碰撞,构造6轮和12轮差分特征;然后,计算轮函数f3的差分表,并在特定差分特征的基础上扩充3轮,从而确定密文差分与f3的输入、输出差分的关系;最后,选取符合条件的明文进行加密,根据密文差分计算f3的输入、输出差分值,并查寻差分表找到对应的输入、输出对,从而获取子密钥。在两个S盒碰撞的情况下,所提攻击实现了9轮Blow-CAST-Fish算法的差分攻击,比对比攻击多1轮,时间复杂度由2107.9降低到274;而在单个S盒碰撞的情况下,所提攻击实现了15轮Blow-CAST-Fish算法的差分攻击,与对比攻击相比,虽然攻击轮数减少了1轮,但弱密钥比例由2-52.4提高到2-42,数据复杂度由254降低到247。测试结果表明,在相同差分特征基础上,基于差分表的攻击的攻击效率更高。

关键词: Blow-CAST-Fish算法, 差分特征, 差分表, 轮函数, 密钥恢复

Abstract:

Aiming at the problems of limited attack rounds and high attack complexity of Blow-CAST-Fish (Blow-C.Adams S.Tavares-Fish) algorithm, a key recovery attack of Blow-CAST-Fish algorithm based on differential table was proposed. Firstly, after analyzing the collision of S-box, based on the collision of two S-boxes and a single S-box respectively, the 6-round and 12-round differential characteristics were constructed. Secondly, the differential tables of f3 were calculated, and three rounds were expanded based on the specific differential characteristic, thereby determining the relationship between ciphertext difference and the input and output differences of f3. Finally, the plaintexts meeting the conditions were selected to encrypt, the input and output differences of f3 were calculated according to the ciphertext difference, and the corresponding input and output pairs were found by querying the differential table, as a result, the subkeys were obtained. At the situation of two S-boxes collision, the proposed attack completed a differential attack of 9-round Blow-CAST-Fish algorithm, compared with the comparison attack, the number of attack rounds was increased by one, and the time complexity was reduced from 2107.9 to 274. At the situation of single S-box collision, the proposed attack completed a differential attack of 15-round Blow-CAST-Fish algorithm, compared with the comparison attack, although the number of attack rounds was reduced by one, the proportion of weak keys was increased from 2-52.4 to 2-42 and the data complexity was reduced from 254 to 247. The test results show that the attack based on differential table can increase the efficiency of attack based on the same differential characteristics.

Key words: Blow-CAST-Fish (Blow-C.Adams S.Tavares-Fish) algorithm, differential characteristic, differential table, round function, key recovery

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