jk.rar_JK密码_密码学_流密码c++实现

#include <iostream> using namespace std; //return next state unsigned char fn_feedback(unsigned char n, unsigned char c, unsigned char curr_state) { unsigned char t = c & curr_state; unsigned char s = t & (unsigned char)128; //get first bit for(int i =1; i< n; i++) { s = s ^ ( (t << i) & (unsigned char)128 ); } return (unsigned char)((curr_state << 1) | (s >> (n-1))); //return next state } void lfsr_output_byte(int n, unsigned char c, unsigned char init_state, unsigned char output_bytes[], int byte_length) { unsigned char next_state = init_state; for(int i = 0; i < byte_length; i++) { unsigned char temp = (unsigned char)0; for(int j=0; j< 8; j++) { temp = temp | ( (next_state & (unsigned char)128) >> j ); next_state = fn_feedback(n, c, next_state); } output_bytes[i] = temp; } } //output a char type of data in binary way void output_binary(unsigned char c) { for(int i=0; i< 8; i++) { if( (c<< i) & (unsigned char)128 ) cout << "1"; else cout << "0"; } } void Geffe(unsigned char buf[], unsigned char buf1[], unsigned char buf2[], unsigned char b[]) { for(int i=0; i< 10; i++) { b[i]=buf[i]*buf1[i]+buf2[i]*buf1[i]+buf2[i]; output_binary( (unsigned char)b[i]); } } void JK(unsigned char buf[],unsigned char buf1[],unsigned char c[]) { for(int i=1; i< 11; i++) { c[i]=(buf[i]+buf1[i]+1)*c[i-1]+buf[i]; output_binary( (unsigned char)c[i]); } } void cypt(unsigned char b[]) { unsigned char cypher[10],cyph[10]; cout<<"input the cyphertext:"; cin>>cypher; int j; for(j=0;cypher[j]!='\0';j++) { cyph[j]=cypher[j]^b[j]; cout<<cyph[j]; } cout<<endl; for(int k=0;k<j;k++) { cypher[k]=cyph[k]^b[k]; cout<<cypher[k]; } cout<<endl; } int main(int argc, char* argv[]) { unsigned char buf[10],buf1[10],buf2[10],b[100],c[100]; // 函数f 初始状态152 lfsr_output_byte(5,(unsigned char)144,(unsigned char)152, buf, 10); lfsr_output_byte(5,(unsigned char)44,(unsigned char)152, buf1, 10); lfsr_output_byte(5,(unsigned char)24,(unsigned char)152, buf2, 10); Geffe(buf,buf1,buf2,b); cout<<endl; c[0]=0; JK(buf,buf1,c); cout<<endl; cout<<"Geffe operate:"<<endl; cypt(b); cout<<endl; cout<<"J-K operate:"<<endl; cypt(c); return 0; }