《计算机应用》唯一官方网站 ›› 2023, Vol. 43 ›› Issue (9): 2784-2788.DOI: 10.11772/j.issn.1001-9081.2022091395

• 网络空间安全 • 上一篇    下一篇

缩减轮的超轻量级分组密码算法PFP的不可能差分分析

赵光耀1, 沈璇2(), 余波1, 易晨晖1, 李祯2   

  1. 1.湖南信息学院 电子科学与工程学院,长沙 410151
    2.国防科技大学 信息通信学院,武汉 430010
  • 收稿日期:2022-09-20 修回日期:2022-12-05 接受日期:2022-12-15 发布日期:2023-02-28 出版日期:2023-09-10
  • 通讯作者: 沈璇
  • 作者简介:赵光耀(1982—),男,湖南湘潭人,高级工程师,博士,CCF会员,主要研究方向:密码分析、机器学习
    余波(1969—),男,湖南常德人,教授,硕士,CCF会员,主要研究方向:智能算法
    易晨晖(1980—),女,湖南娄底人,高级实验师,硕士,主要研究方向:智能算法
    李祯(1991—),男,江西赣州人,副教授,博士,主要研究方向:智能与无人系统仿真。
  • 基金资助:
    国家自然科学基金资助项目(62002370);国防科技大学学校科研计划项目(ZK21-36)

Impossible differential cryptanalysis of reduced-round ultra-lightweight block cipher PFP

Guangyao ZHAO1, Xuan SHEN2(), Bo YU1, Chenhui YI1, Zhen LI2   

  1. 1.School of Electronic Science and Engineering,Hunan University of Information Technology,Changsha Hunan 410151,China
    2.College of Information and Communication,National University of Defense Technology,Wuhan Hubei 430010,China
  • Received:2022-09-20 Revised:2022-12-05 Accepted:2022-12-15 Online:2023-02-28 Published:2023-09-10
  • Contact: Xuan SHEN
  • About author:ZHAO Guangyao, born in 1982, Ph. D., senior engineer. His research interests include cryptanalysis, machine learning.
    YU Bo, born in 1969, Ph. D., professor. His research interests include intelligent algorithm.
    YI Chenhui, born in 1980, M. S., senior experimentalist. Her research interests include intelligent algorithm.
    LI Zhen, born in 1991, Ph. D., associate professor. His research interests include simulation of intelligent and unmanned system.
  • Supported by:
    National Natural Science Foundation of China(62002370);Research Program of National University of Defense Technology(ZK21-36)

摘要:

基于Feistel结构的轻量级分组密码算法PFP适用于物联网终端设备等资源极端受限环境。目前对PFP算法不可能差分分析的最好结果是利用7轮不可能差分区分器攻击9轮PFP算法,这样可恢复36 b的种子密钥。为了更准确地评估PFP算法抵抗不可能差分分析的能力,对PFP算法结构进行研究。首先,通过分析轮函数中S盒的差分分布特性,找到了概率为1的两组差分;其次,结合置换层特点,构造出一组包含16条不可能差分的7轮不可能差分区分器;最后,基于构建的7轮不可能差分区分器,对9轮PFP算法进行不可能差分分析以恢复40 b种子密钥,并提出对10轮PFP算法的不可能差分分析方法来恢复52 b种子密钥。结果表明,所提方法在区分器数量、分析轮数、恢复密钥比特数等方面均有较大改善。

关键词: 轻量级, 分组密码, PFP, 不可能差分, 密码分析

Abstract:

The ultra-lightweight block cipher PFP based on Feistel structure is suitable for extremely resource-constrained environments such as internet of things terminal devices. Up to now, the best impossible differential cryptanalysis of PFP is to use 7-round impossible differential distinguishers to attack the 9-round PFP, which can recover 36-bit master key. The structure of PFP was studied in order to evaluate the ability for resisting impossible differential cryptanalysis more accurately. Firstly, by analyzing the differential distribution characteristics of S-box in the round function, two groups of differences with probability 1 were found. Secondly, combined with the characteristics of the permutation layer, a set of 7-round impossible differential distinguishers containing 16 impossible differences was constructed. Finally, based on the constructed 7-round impossible differential distinguishers, 40-bit master key was recovered by performing impossible differential cryptanalysis on the 9-round PFP, and an impossible differential cryptanalysis method for 10-round PFP was proposed to recover 52-bit master key. The results show that the proposed method has great improvement in terms of the number of distinguishers, the number of cryptanalysis rounds, and the number of bits of the recovered key.

Key words: lightweight, block cipher, PFP, impossible differential, cryptanalysis

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