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)。
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
Abstract: 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(24n) to O(1).
Key words:
linear approximation,
macrocosm approximation,
addition modulo 2n,
XOR,
interpolation function,
sum probability distribution
中图分类号:
买应霞, 陈士伟, 李席斌. 异或加整体逼近模2n加差值函数的和概率分布[J]. 计算机工程, 2013, 39(4): 128-131.
MAI Ying-Xia, CHEN Shi-Wei, LI Xi-Bin. Sum Probability Distribution of Interpolation Function by Macrocosm Approximation of Addition Modulo 2n with XOR[J]. Computer Engineering, 2013, 39(4): 128-131.