重新考察类RECTANGLE对称密码算法的设计OA

Lightweight block cipher TANGRAM as well as authenticated encryption with associated data and hashing algorithms KNOT are designed based on RECTANGLE algorithm.By selecting S-boxes and shift offsets of linear later,two key evaluation indicators,the maximum differential prob-ability of differential trails and the maximum linear correlation square of linear trails,are maximized.Nevertheless,the differential trails and linear trails of these algorithms always contain iterative trails,and such iterative trails may have a clustering effect,which can be measured by the minimum average weight growth.Taking advantage of the feature that this indicator can be quickly calculated,this study revisits the S-box and shift offsets selection process of RECTANGLE-like cipher,in which all possibilities of shift offsets are taking into consideration,and the clustering effect of iterative trails is also taken into account.Finally,the study proposes that replacing the S-box in TANGRAM and KNOT with the S-box of RECTANGLE can enhance their resistances to differential cryptanalysis and linear cryptanalysis.