Feistel加密算法c++代码
时间: 2023-07-09 08:03:47 浏览: 53
以下是Feistel加密算法的C++代码实现:
```c++
#include <iostream>
#include <cstring>
#include <bitset>
#include <algorithm>
using namespace std;
const int N = 10010;
// 将字符串转换为二进制位串
bitset<N> str2bin(string s) {
bitset<N> res;
int len = s.length();
for (int i = 0; i < len; i++) {
bitset<8> b(s[i]); // 将字符转换为8位二进制串
for (int j = 0; j < 8; j++) {
res[i * 8 + j] = b[7 - j];
}
}
return res;
}
// 将二进制位串转换为字符串
string bin2str(bitset<N> b) {
string res;
int len = b.count() / 8;
for (int i = 0; i < len; i++) {
bitset<8> tmp;
for (int j = 0; j < 8; j++) {
tmp[7 - j] = b[i * 8 + j];
}
res += char(tmp.to_ulong()); // 将8位二进制串转换为字符
}
return res;
}
// Feistel加密算法
bitset<N> Feistel(bitset<N> plaintext, bitset<N> key, int rounds) {
int half_size = plaintext.size() / 2;
// 将明文分为左右两部分
bitset<N> left = plaintext >> half_size;
bitset<N> right = plaintext & ((1 << half_size) - 1);
// 迭代加密
for (int i = 0; i < rounds; i++) {
bitset<N> tmp = left;
left = right;
right = tmp ^ (right ^ key);
}
// 将左右两部分合并
bitset<N> ciphertext = (left << half_size) | right;
return ciphertext;
}
int main() {
string plaintext, key;
int rounds;
cout << "请输入明文:";
getline(cin, plaintext);
cout << "请输入密钥:";
cin >> key;
cout << "请输入加密轮数:";
cin >> rounds;
// 将明文和密钥转换为二进制位串
bitset<N> plaintext_bin = str2bin(plaintext);
bitset<N> key_bin = str2bin(key);
// 对明文进行加密
bitset<N> ciphertext_bin = Feistel(plaintext_bin, key_bin, rounds);
// 将密文转换为字符串
string ciphertext = bin2str(ciphertext_bin);
cout << "加密结果:" << ciphertext << endl;
return 0;
}
```
其中,`str2bin()`函数将字符串转换为二进制位串,`bin2str()`函数将二进制位串转换为字符串,`Feistel()`函数实现了Feistel加密算法。在`main()`函数中,用户输入明文、密钥和加密轮数,程序对明文进行加密,并输出密文。