通过替换字符在PHP中创建简单的加密代码

问题描述：

I'm new in PHP.

I want to make a simple encryption function in PHP that change a string to new string by changing characters.

For doing this, I create two arrays of characters.

In the first array I assign all characters and sorting them like :

$true_chars = array('a','b','c','d','e');

In another array, I change the position of the characters.

$fake_chars = array('c','d','a','e','b');

My goal is, when the function gets the right string, change the string characters by Replacing the second array.

For example, my string is acdc , the encryption function compares acdc characters by the first array to get true index's (if need) and then replace by second array index and change it to caea.

how actually can I do that?

我是PHP新手。 p>

我想做一个简单的事情 PHP中的加密函数，通过更改字符将字符串更改为新字符串。 p>

为此，我创建了两个字符数组。 p>

在第一个数组我分配所有字符并将它们排序为： p>

  $ true_chars = array（'a'，'b'，'c'，'d'，'e'）  ; 
  code>  pre> 
 
 在另一个数组中，我改变了字符的位置。 p> 
 
 
  $ fake_chars = array（'  c'，'d'，'a'，'e'，'b'）; 
  code>  pre> 
 
 我的目标是，当函数获得正确的字符串时，更改 替换第二个数组的字符串字符。 p> 
 
 
例如，我的字符串是 acdc  code>，加密函数比较 acdc  code>字符 第一个数组获取真正的索引（如果需要）然后替换为第二个数组索引并将其更改为 caea  code>。 p> 
 
 
我实际上该怎么做？  p> 
  div>

答

Start by creating an array that maps the original character to the encoded character:

$chars = [
    'a' => 'c',
    'b' => 'd',
    'c' => 'a',
    'd' => 'e',
    'e' => 'b',
];

Then you loop through the string and replace the characters:

$original  = 'acdc';

// Encrypt
$encrypted = '';

for ($i = 0; $i < strlen($original); $i++) {
    // If we find the character in our mapping array, use the mapped character.
    // If not, let's use the original character.
    $encrypted .= array_key_exists($original[$i], $chars) 
        ? $chars[$original[$i]]
        : $original[$i];
}

print_r($encrypted);
// caea

To decrypt it, we just needs to check if the character exists in the array and use the key instead:

// Decrypt
$decrypted = '';
for ($i = 0; $i < strlen($encrypted); $i++) {
    // Find the correct key
    $key = array_search($encrypted[$i], $chars);

    // If the character existed, use the key.
    // If not, use the original character.
    $decrypted .= $key !== false 
        ? $key
        : $encrypted[$i];
}

print_r($decrypted);
// acdc

Demo: https://3v4l.org/vQAZj

通过替换字符在PHP中创建简单的加密代码

相关推荐