Rectangle Attack Against Type-I Generalized Feistel Structures  

作　　者：ZHANG Yi LIU Guoqiang SHEN Xuan LI Chao 

机构地区：[1]College of Liberal Arts and Sciences,National University of Defense Technology,Changsha 410073,China [2]College of Information and Communication,National University of Defense Technology,Wuhan 430010,China [3]State Key Laboratory of Information Security,Institute of Information Engineering,Chinese Academy of Sciences,Beijing 100093,China [4]Hunan Engineering Research Center of Commercial Cryptography Theory and Technology Innovation,Changsha 410073,China

出　　处：《Chinese Journal of Electronics》2022年第4期713-720,共8页电子学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(62172427,61702537,61772545,62002370);State Key Laboratory of Information Security(2020-MS-02);Scientific Research Plan of National University of Defense Technology(ZK21-36).

摘　　要：Type-I generalized Feistel networks(GFN)are widely used frameworks in symmetric-key primitive designs such as CAST-256 and Lesamnta.Different from the extensive studies focusing on specific block cipher instances,the analysis against Type-I GFN structures gives generic security evaluation of the basic frameworks and concentrates more on the effect of linear transformation.Currently,works in this field mainly evaluate the security against impossible differential attack,zero-correlation linear attack,meet-in-the-middle attack and yoyo game attack,while its security evaluation against rectangle attack is still missing.In this paper,we filled this gap and gave the first structural analytical results of Type-I GFN against rectangle attack.By exploiting its structural properties,we proved there exists a boomerang switch for Type-I GFN for the first time,which is independent of the round functions.Then we turned the boomerang switch into chosen plaintext setting and proposed a new rectangle attack model.By appending 1 more round in the beginning of the boomerang switch,we constructed a rectangle distinguisher and a key recovery attack could be performed.

关 键 词：Block cipher structures Rectangle attack Boomerang switch Structural attack Generalized Feistel networks 

分 类 号：TN918.1[电子电信—通信与信息系统]