简单的文本加密

#include<iostream>
#include<string>
#include<ctime>
using namespace std;

int Encryption(string &MingWen,int seed){ //加密

for (int i = 0; i < MingWen.size(); i++)
{
MingWen[i] = ~MingWen[i] +seed;
}
return 0;

}
int Decryption(string& MiWen,int seed){

for (int i = 0; i < MiWen.size(); i++)
{
MiWen[i] = ~MiWen[i] + seed;
}
return 0;
}
int main()
{
string txt;
srand((unsigned)time(NULL));
int seed = rand();

getline(cin, txt);
Encryption(txt, seed);
cout << "密文:" << txt << endl;
Decryption(txt, seed);
cout << "明文:" << txt << endl;
system("pause");
return 0;

}