Example of encryption and decryption algorithm using php combined with md5

The example in this article describes the encryption and decryption algorithm of php combined with md5. Share it with everyone for your reference, the details are as follows:

<?php
/*
* Created on 2016-9-30
*
*/
function encrypt($data, $key)
{
 $key = md5($key);
  $x = 0;
  $len = strlen($data);
  $l = strlen($key);
  for ($i = 0; $i < $len; $i++)
  {
    if ($x == $l)
    {
     $x = 0;
    }
    $char .= $key{$x};
    $x++;
  }
  for ($i = 0; $i < $len; $i++)
  {
    $str .= chr(ord($data{$i}) + (ord($char{$i})) % 256);
  }
  return base64_encode($str);
}
function decrypt($data, $key)
{
 $key = md5($key);
  $x = 0;
  $data = base64_decode($data);
  $len = strlen($data);
  $l = strlen($key);
  for ($i = 0; $i < $len; $i++)
  {
    if ($x == $l)
    {
     $x = 0;
    }
    $char .= substr($key, $x, 1);
    $x++;
  }
  for ($i = 0; $i < $len; $i++)
  {
    if (ord(substr($data, $i, 1)) < ord(substr($char, $i, 1)))
    {
      $str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1)));
    }
    else
    {
      $str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1)));
    }
  }
  return $str;
}
$data = &#39;中文网www.php.cn&#39;; // 被加密信息
$data=iconv("gbk","utf-8",$data);
$key = &#39;www.jb51.net&#39;;   // 密钥
$encrypt = encrypt($data, $key);
$decrypt = decrypt($encrypt, $key);
echo $encrypt, "<br/>", $decrypt;
?>

The running results are as follows:

TrXMTM8SFB3DGhTr2qeuYqOXZmpmn8mo
中文网www.php.cn

I hope this article will be helpful to everyone in PHP programming.

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