投影HFE^-体制的安全性分析

Cryptanalysis of Projected HFE^- Scheme

针对投影HFE-体制的安全性,提出了一种代数攻击方法,并指出该体制存在着弱密钥。攻击方法的基本思想是利用投影HFE-体制在扩域上的代数结构,并用私钥仿射部分和私钥结构的缺陷寻找大量的线性方程。研究结果表明,该攻击方法在这种弱密钥情况下可以有效地恢复部分私钥。

For the security of projected HFE- cryptographic scheme,an algebraic method was proposed to attack the scheme and pointed out its weak keys.The basic idea of the attack utilized the underlying algebraic structure of projected HFE- scheme over the extension field,and applyed the affine part of private keys and the weakness caused by the structure of private keys to find a large number of linear equations.The result indicated that the attack can recover the part of private keys efficiently once weak keys are used.