WAS:improved white-box cryptographic algorithm over AS iteration  

作　　者：Yatao Yang Yuying Zhai Hui Dong Yanshuo Zhang 

机构地区：[1]Department of Electronic and Communication Engineering,Beijing Electronic Science and Technology Institute,Beijing 100070,China [2]School of Telecommunication Engineering,Xidian University,Xi’an 710071,China

出　　处：《Cybersecurity》2025年第1期142-152,共11页网络空间安全科学与技术(英文)

基　　金：supported by Beijing Natural Science Foundation(No:4232034);the Fundamental Research Funds for the Central Universities(No:328202222).

摘　　要：The attacker in white-box model has full access to software implementation of a cryptographic algorithm and full control over its execution environment.In order to solve the issues of high storage cost and inadequate security about most current white-box cryptographic schemes,WAS,an improved white-box cryptographic algorithm over AS iteration is proposed.This scheme utilizes the AS iterative structure to construct a lookup table with a fvelayer ASASA structure,and the maximum distance separable matrix is used as a linear layer to achieve complete difusion in a small number of rounds.Attackers can be prevented from recovering the key under black-box model.The length of nonlinear layer S and afne layer A in lookup table is 16 bits,which efectively avoids decomposition attack against the ASASA structure and makes the algorithm possess anti-key extraction security under the whitebox model,while WAS possesses weak white-box(32 KB,112)-space hardness to satisfy anti-code lifting security.WAS has provable security and better storage cost than existing schemes,with the same anti-key extraction security and anti-code lifting security,only 128 KB of memory space is required in WAS,which is only 14%of SPACE-16 algorithm and 33%of Yoroi-16 algorithm.

关 键 词：White-box cryptography Block cipher Substitution permutation network structure Anti-key extraction Anti-code lifting 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]