二元最佳扩散矩阵的一种构造方法

Construction method for binary matrix with maximum branch number

扩散结构的好坏直接影响了分组密码的扩散速度和安全强度,以分支数尽可能大的线性变换为分组密码算法的扩散结构是设计分组密码的一种重要方法,线性变换的构造可通过可逆矩阵的构造完成。针对块数为8的扩散结构进行了研究,给出了分支数达到最大的二元矩阵的构造方法和构造算法。该算法运行速度很快,能够满足实际的应用需要。

The diffusion structure has important impact on the rate of the diffusion and safety intensity for block cipher.Using the linear transform which has branch numbers as large as possible as the diffusion structure is a main method to devise block cipher.The linear transform is usually achieved by constructing the invertible matrix.A kind of diffusion structure with eight blocks is analyzed,and moreover,a new method to construct binary matrix with maximal branch number is proposed and the corresponding algorithm is proposed too.The algorithm runs fast which can satisfy the applying requirement practically.