摘要
为求解密码算法中异或加整体逼近模2n加运算所得差值函数之和的概率分布问题,利用概率分布的定义,通过直接统计满足条件变量的计数,给出2个差值函数之和的概率分布,并进一步提出2个差值函数之和的概率平方和计算公式,将其计算复杂度由O(24n)降为O(1)。
Aiming at the sum probability distribution problem of the interplation function produced by macrocosm approximation of addition modulo 2n with XOR, this paper utilizes the definition of the probability distribution, and gives out the computation formula of the probability distributions of two noise functions, through counting the number of variables satisfying the conditions. Then this paper gives out the computation formula of the square sum of the probability distribution of the sum of two noise functions, which reduces the computation complexity from O（2^4n） to O（1）.
出处
《计算机工程》
CAS
CSCD
2013年第4期128-131,共4页
Computer Engineering
关键词
线性逼近
整体逼近
模2n加
异或加
差值函数
和概率分布
linear approximation
macrocosm approximation
addition modulo 2^n
XOR
interpolation function
sum probabilitydistribution
作者简介
买应霞（1970-），女，讲师，主研方向：密码学，信息安全；E—mail：diriglinl987dl@163．com
陈士伟，博士
李席斌，硕士
