摘要
研究了流密码体制中抗攻击前馈网络的构造。通过对有限状态机（ＦＳＭ）输出函数的Ｗａｌｓｈ谱及Ｎ元布尔函数是Ｎ－１阶相关免疫的充要定理的讨论，证明了ＦＳＭ组合器是Ｎ１阶相关免疫的。论述了用Ｂｅｎｔ函数做前馈网络的非线性组合函数可很好的抗相关攻击和线性逼近攻击。文中给出一种可用其实现任意Ｎ元布尔函数的多功能程控逻辑门，使布尔函数的线路实现极为经济。最后用ＦＳＭ组合器及给出的多功能程控逻辑门构造了实现一大类Ｂｅｎｔ函数的前馈网络。此流密码体制具有强的抗攻击能力。
The construction of feedforward network against attacks in stream ciphers isstudied in this paper. It is proved that the finite-state-machine (FSM)-combiner is (N-1)th-order correlation-immune by discussions of the Walsh spectral on output function of FSMand the theorem of necessary and sufficient condition on the Boolean function f(x), Whichfor N binary variables is (N-1)th-order correlation-immune. It is dealt with that, by usingBent functions as nonlinear combining function of the feedforward network, it can resist correlation attack and linear approximation attack very well. The functions programming logicgate is given. Arbitrary Boolean function for N binary variables is realized by the gate,which is very economical on the realized circuit. Finally the feed forward network to realizeone great group of Bent function is presented, that is constructed by FSM-combiner and thefunctions programming logic gate. The stream ciphers scheme can resist attacks strongly.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
1996年第9期106-111,共6页
Journal of Tsinghua University(Science and Technology)
关键词
流密码
有限状态机
BENT函数
前馈网络
组合器
stream cipher
FSM (finite-state-machine)
Bent function
feedforward network
logic gate
