In this paper, we view filter generators as Boolean networks (BNs), and discuss their power-analysis-based side-channel analysis. An incompletely specified binary sequence always contains some bits called unnecessary bits comprising 1 or 0. Our motivation for considering this type of sequence is to reduce direct dependencies between side-channel information and key sequences. An algorithm is proposed to determine the unnecessary bits to increase the key search time required for adversaries rather than simply turning all unnecessary bits to 0 (or 1). Then, to reduce area dissipation, under the framework of semi-tensor product (STP) of matrices, the problem of constructing filter generators with minimum number of stages is converted into the one of determining the corresponding transition matrices. Compared with the existing results, the lower bound of the minimum number of stages is provided, which can reduce the exhaustive search time required to find it. Finally, one example is used to illustrate the efficacy of the proposed algorithm.

在本文中，我们将过滤器生成器视为布尔网络（BN），并讨论了基于功率分析的边信道分析。不完整指定的二进制序列始终包含一些称为不必要比特的比特，其中包括1或0。考虑这种类型的序列的动机是为了减少副信道信息与密钥序列之间的直接依赖性。提出了一种算法来确定不必要的比特，以增加对手所需的密钥搜索时间，而不是简单地将所有不必要的比特变为0（或1）。然后，为了减少面积耗散，在矩阵的半张量积（STP）的框架下，构造具有最少级数的滤波器生成器的问题被转换为确定对应的过渡矩阵之一。与现有结果相比，提供了最小级数的下限，这可以减少找到它所需的详尽搜索时间。最后，通过一个例子说明了该算法的有效性。