encrypt/decrypt

what the best way to encrypt alphanumeric string to another alphanumeric (no unique char)? and also decryptable...

thx

 

If you don't have to decrypt it you can just use md5() or something like it, for example for passwords.

 

i need decryptable one, thx

 

You could use str_rot13().

 

/**
 * Encrypt/decrypt url
 * Encrypts and decrypts url
 * Usage example: - 'index.php?A='.encrypt_url("somedata")
 *                - decrypt_url($GET['A'])
 */
function encrypt_url($string) {
        $key = "123abc"; //preset key to use on all encrypt and decrypts.
        $result = '';
   for($i=0; $i<strlen($string); $i++) {
     $char = substr($string, $i, 1);
     $keychar = substr($key, ($i % strlen($key))-1, 1);
     $char = chr(ord($char)+ord($keychar));
     $result.=$char;
   }
   return urlencode(base64_encode($result));
}
function decrypt_url($string) {
        $key = "123abc";
        $result = '';
        $string = base64_decode(urldecode($string));
   for($i=0; $i<strlen($string); $i++) {
     $char = substr($string, $i, 1);
     $keychar = substr($key, ($i % strlen($key))-1, 1);
     $char = chr(ord($char)-ord($keychar));
     $result.=$char;
   }
   return $result;
}

PHP:

 

I just currently installed mcrypt library for a project, Nice one, very hard to decrypt data unless you know the key. But encrypted value has loads of special or must say very special characters

 

@Choller
THX!!
this is exactly what I need!
and its true i use it for url (html get) purpose