《计算机应用》唯一官方网站 ›› 2023, Vol. 43 ›› Issue (8): 2462-2470.DOI: 10.11772/j.issn.1001-9081.2022060886

• 网络空间安全 • 上一篇    

基于神经区分器的KATAN48算法条件差分分析方法

林东东1,2, 李曼曼1,2(), 陈少真1,2   

  1. 1.信息工程大学 网络空间安全学院,郑州 450001
    2.密码科学技术全国重点实验室(国家密码管理局),北京 100878
  • 收稿日期:2022-06-20 修回日期:2022-08-30 接受日期:2022-09-01 发布日期:2022-09-22 出版日期:2023-08-10
  • 通讯作者: 李曼曼
  • 作者简介:林东东(1998—),男,河南邓州人,硕士研究生,主要研究方向:深度学习、智能化分组密码分析
    陈少真(1967—),女,江苏无锡人,教授,博士,主要研究方向:分组密码分析、密码体制识别。
  • 基金资助:
    河南省自然科学基金资助项目(232300421394)

Conditional differential cryptanalysis method of KATAN48 algorithm based on neural distinguishers

Dongdong LIN1,2, Manman LI1,2(), Shaozhen CHEN1,2   

  1. 1.School of Cyber Security,Information Engineering University,Zhengzhou Henan 450001,China
    2.State Key Laboratory of Cryptography (State Cryptography Administration),Beijing 100878,China
  • Received:2022-06-20 Revised:2022-08-30 Accepted:2022-09-01 Online:2022-09-22 Published:2023-08-10
  • Contact: Manman LI
  • About author:LIN Dongdong,born in 1998, M. S. candidate. His research interests include deep learning, intelligent cryptanalysis of block cipher.
    CHEN Shaozhen,born in 1967, Ph. D., professor. Her researchinterests include cryptanalysis of block cipher, cryptosystem identification.
  • Supported by:
    Natural Science Foundation of Henan Province(232300421394)

摘要:

针对KATAN48算法的安全性分析问题,提出了一种基于神经区分器的KATAN48算法条件差分分析方法。首先,研究了多输出差分神经区分器的基本原理,并将它应用于KATAN48算法,根据KATAN48算法的数据格式调整了深度残差神经网络的输入格式和超参数;其次,建立了KATAN48算法的混合整数线性规划(MILP)模型,并用该模型搜索了前加差分路径及相应的约束条件;最后,利用多输出差分神经区分器,至多给出了80轮KATAN48算法的实际密钥恢复攻击结果。实验结果表明,在单密钥下,KATAN48算法的实际攻击的轮数提高了10轮,可恢复的密钥比特数增加了22比特,数据复杂度和时间复杂度分别由234和234降至216.39和219.68。可见,相较于前人单密钥下的实际攻击,所提方法能够有效增加攻击轮数和可恢复的密钥比特数,同时降低攻击的计算复杂度。

关键词: 分组密码, 混合整数线性规划, KATAN算法, 条件差分分析, 神经区分器

Abstract:

Aiming at the security analysis problem of KATAN48 algorithm, a conditional differential cryptanalysis method of KATAN48 algorithm based on neural distinguishers was proposed. First, the basic principle of multiple output differences neural distinguishers was studied and applied to KATAN48 algorithm. According to the data format of KATAN48 algorithm, the input format and hyperparameters of the deep residual neural network were adjusted. Then, the Mixed-Integer Linear Programming (MILP) model of KATAN48 algorithm was established to search the prepended differential paths and the corresponding constraint conditions. At last, using the multiple output differences neural distinguishers, at most 80-round of the practical key recovery attack results of KATAN48 algorithm were given. Experimental results show that in the single key setting, the number of practical attack rounds of KATAN48 algorithm is increased by 10 rounds, the number of recoverable key bits of KATAN48 algorithm is increased by 22 bit and the data complexity and time complexity of KATAN48 algorithm are reduced from 234 and 234 to 216.39 and 219.68 respectively. Compared to the previous practical attack at the single-key setting, the proposed method can effectively increase the number of attack rounds and recoverable key bits, and reduces the computational complexity of attack.

Key words: block cipher, Mixed-Integer Linear Programming (MILP), KATAN algorithm, conditional differential cryptanalysis, neural distinguisher

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