一个53位数的分解

本文描述一个在序列密码设计中有重要意义的５３位数Ｎ＝的素因子分解。按Ｐｏｍｅｒａｎｃｅ－Ｍｏｎｔｇｏｍｅｒｙ多个多项式二次筛算法编写的Ｐａｓｃａｌ程序在一台ＰＣ３８６微机上把Ｎ分解成三个素数之积。此Ｐａｓｃａｌ程序在一台３８６／４８６微机上分解一个６０位数大约需一天左右的时间。

关于有限域上射影特殊线性群的子群格

設G是一个群。如果对G中任意两个子群A和B,用A∩B和A∪B分别表示二者的交和二者所生成的子群,那末G的子群的全体对这两个运算形成一个格。这个格称为群G的子群格,記作Λ(G)。

A CRYPTOGRAPHIC STUDY ON S—BOXES OF DES TYPE Ⅱ——AN ENTROPY LEAKAGE ANALYSIS FOR THE KEY

The concept of key-entropy drop in an S-box is introduced.It is established that theoutput functions of the permutations composing an S-box belong to three patterns of key-entropydrop.An analysis of the distribution of the key-entropy drop patterns in the 8 S-boxes in the DEShas been made.

含错线性序列的极大似然纠正

本文中讨论二元序列时,其元素间的运算均在二元域 F_2={0,1}中进行.设α=(α_t)_t≥0是 F_2上由多项式 c(x)=1+c_1x+…+c_(d-1)x^(d-1)+x^d 生成的线性序列,即有α_t+c_1α_(t+1)+…+C_(d-1)α_(t+d-1)+a_(t+d)=0,t≥0.(1)如果有二元干扰序列 e=(e_t)_(t≥0)迭加于α,其中 e_0,e_1,…是独立同分布的,Prob(e_t=1)=s<1/2,则迭合序列 b=(b_t)_(t≥0)=(α_t+e_t)t≥0称为α的含错序列,其错误率为 s.

A CRYPTOGRAPHIC STUDY ON S—BOXES OF DES TYPE Ⅰ AN INTEGRATED ANALYSIS OF THE DESIGN CRITERIA FOR S-BOXES

An integrated analysis of the design criteria for the S-boxes used in the DES is made.Among others,the exclusion principle between the degree of nonlinearity and the degree of I/O—correlation immunity for partial variables is established.