????????XOR密码，也被称为异或密码，是一种简单和常见的加密算法。XOR操作（异或操作）是一种逻辑运算，它比较两个输入并输出一个结果，结果为1的条件是两个输入不相等。
????????XOR密码的原理是将明文与密钥按位进行异或操作，生成加密后的密文。解密时，再将密文与相同的密钥按位进行异或操作，就能还原出原始的明文。
XOR密码有以下特点：
下面是两个简单的示例代码，展示了如何使用XOR密码进行加密和解密：?
示例一：
/**
?* @file xor_cipher.cpp
?* @brief Implementation of [XOR cipher](https://en.wikipedia.org/wiki/XOR_cipher) algorithm.
?*
?* @details
?* In cryptography, the simple XOR cipher is a type of additive cipher, an encryption?
?* algorithm that operates according to the principles:?
?*
?* * \f$A {\oplus} 0 = A\f$
?* * \f$A {\oplus} A = 0\f$
?* * \f$ (A {\oplus} B) {\oplus} C = A {\oplus} (B {\oplus} C)\f$
?* * \f$ (B {\oplus} A) {\oplus} B = B {\oplus} 0 = B \f$
?*?
?*?
?* where \f$\oplus\f$ symbol denotes the exclusive disjunction (XOR) operation.
?* This operation is sometimes called modulus 2 addition (or subtraction, which is identical).
?* With this logic, a string of text can be encrypted by applying the bitwise XOR operator to
?* every character using a given key. To decrypt the output, merely reapplying the XOR function?
?* with the key will remove the cipher.
?*?
?* ### Algorithm
?* Choose the key for encryption and apply XOR operation to each character of a string.?
?* Reapplying XOR operation to each character of encrypted string will give original string back.
?*?
?* \note This program implements XOR Cipher for string with ASCII characters.?
?*?
?* @author [Deep Raval](https://github.com/imdeep2905)
?*/
#include <iostream>
#include <string>
#include <cassert>
/** \namespace ciphers
?* \brief Algorithms for encryption and decryption
?*/
namespace ciphers {
? ? /** \namespace XOR
? ? ?* \brief Functions for [XOR cipher](https://en.wikipedia.org/wiki/XOR_cipher) algorithm.
? ? ?*/
? ? namespace XOR { ??
? ? ? ? /**
? ? ? ? ?* Encrypt given text using XOR cipher.
? ? ? ? ?* @param text text to be encrypted
? ? ? ? ?* @param key to be used for encyption
? ? ? ? ?* @return new encrypted text
? ? ? ? ?*/
? ? ? ? std::string encrypt (const std::string &text, const int &key) {
? ? ? ? ? ? std::string encrypted_text = ""; // Empty string to store encrypted text
? ? ? ? ? ? for (auto &c: text) { // Going through each character
? ? ? ? ? ? ? ? char encrypted_char = char(c ^ key); // Applying encyption
? ? ? ? ? ? ? ? encrypted_text += encrypted_char; // Appending encrypted character
? ? ? ? ? ? }
? ? ? ? ? ? return encrypted_text; // Returning encrypted text
? ? ? ? }
? ? ? ? /**
? ? ? ? ?* Decrypt given text using XOR cipher.
? ? ? ? ?* @param text text to be encrypted
? ? ? ? ?* @param key to be used for decryption
? ? ? ? ?* @return new decrypted text
? ? ? ? ?*/ ? ? ? ?
? ? ? ? std::string decrypt (const std::string &text, const int &key) {
? ? ? ? ? ? std::string decrypted_text = ""; // Empty string to store decrypted text
? ? ? ? ? ? for (auto &c : text) { // Going through each character
? ? ? ? ? ? ? ? char decrypted_char = char(c ^ key); // Applying decryption
? ? ? ? ? ? ? ? decrypted_text += decrypted_char; // Appending decrypted character
? ? ? ? ? ? }
? ? ? ? ? ? return decrypted_text; // Returning decrypted text
? ? ? ? }
? ? } // namespace XOR
} // namespace ciphers
/**
?* Function to test above algorithm
?*/
void test() {
? ? // Test 1
? ? std::string text1 = "Whipalsh! : Do watch this movie...";
? ? std::string encrypted1 = ciphers::XOR::encrypt(text1, 17);
? ? std::string decrypted1 = ciphers::XOR::decrypt(encrypted1, 17);
? ? assert(text1 == decrypted1);
? ? std::cout << "Original text : " << text1;
? ? std::cout << " , Encrypted text (with key = 17) : " << encrypted1;
? ? std::cout << " , Decrypted text : "<< decrypted1 << std::endl;
? ? // Test 2
? ? std::string text2 = "->Valar M0rghulis<-";
? ? std::string encrypted2 = ciphers::XOR::encrypt(text2, 29);
? ? std::string decrypted2 = ciphers::XOR::decrypt(encrypted2, 29);
? ? assert(text2 == decrypted2);
? ? std::cout << "Original text : " << text2;
? ? std::cout << " , Encrypted text (with key = 29) : " << encrypted2;
? ? std::cout << " , Decrypted text : "<< decrypted2 << std::endl;
}
/** Driver Code */
int main() {
? ? // Testing
? ? test();
? ? return 0;
}
示例二：
#include <iostream>
#include <string>
std::string xorEncryptDecrypt(const std::string& text, const std::string& key)
{
? ? std::string result = text;
? ? for (int i = 0; i < text.length(); i++)
? ? {
? ? ? ? result[i] = text[i] ^ key[i % key.length()];
? ? }
? ? return result;
}
int main()
{
? ? std::string plainText = "Hello World";
? ? std::string key = "SecretKey";
? ? std::string encryptedText = xorEncryptDecrypt(plainText, key);
? ? std::cout << "Encrypted Text: " << encryptedText << std::endl;
? ? std::string decryptedText = xorEncryptDecrypt(encryptedText, key);
? ? std::cout << "Decrypted Text: " << decryptedText << std::endl;
? ? return 0;
}
????????在上面的代码中，`xorEncryptDecrypt`函数接受明文和密钥作为参数，并将其转换为密文或解密为明文。加密和解密使用相同的操作：针对明文和密钥的每个字符，执行异或操作。最后，将结果返回为字符串。
????????请注意，XOR密码并不是一个强大的加密算法，不适用于保护敏感数据。在实际应用中，应该使用更安全的加密算法，如AES或RSA。