基于白盒CLEFIA实现的软件防篡改方案

Software Tamper Resistance Scheme Based on White-Box CLEFIA Implementation

2002年,CHOW等人根据数字版权管理(Digital Rights Management,DRM)应用场景定义了白盒攻击环境的概念,并将其模型化为一种极端的攻击模型,即白盒模型。白盒模型颠覆了以往攻击模型中对攻击者能力的诸多限制,从软件保护角度考虑,攻击者被认为拥有对目标软件及其执行的完全控制权。因此,在白盒模型中,数字版权管理系统中的设备,如智能卡、机顶盒等都存在被攻击者篡改的可能。文章基于CLEFIA算法的白盒实现方案,为数字版权管理系统提供一种软件防篡改方案。该方案将软件的二进制代码文件所解释的查找表隐藏在CLEFIA算法的白盒实现方案的查找表集合中,使软件的防篡改安全性与CLEFIA算法的白盒实现方案的加解密正确性结合在一起。一旦软件发生篡改,CLEFIA算法的白盒实现方案的加解密结果将产生错误。CLEFIA算法白盒实现方案的明密文对也将发生变化,而攻击者很难对其进行修复。

In 2002,Chow et al.defined the concept of white-box attack context according to the application scenario of digital rights management(DRM),and modeled it as an extreme attack model,namely white-box model.The white-box model subverts many restrictions on the ability of the attacker in the previous attack model.From the point of view of software protection,the attacker is considered to have complete control over the target software and its execution.Therefore,in the white-box model,devices in digital rights management systems,such as smart cards and set-top boxes,may be tampered with by attackers.Based on the white-box implementation scheme of CLEFIA algorithm,this paper proposed a software tamper-resistance scheme for digital rights management system.This scheme hided the lookup table interpreted by the binary code file of the software in the lookup table set of the white-box implementation scheme of the CLEFIA algorithm,so that the tamper-resistance security of the software was combined with the encryption and decryption correctness of the white-box implementation scheme of the CLEFIA algorithm.If the software suffers tampering,an error will occur in the encryption and decryption result of the white-box implementation of CLEFIA algorithm.In addition,it is difficult for the attacker to repair the correctness of the encryption and decryption of the white-box implementation of the CLEFIA algorithm.