How good are the encryption features?

Question

PHP

Hi all. I wanted to ask how good these encryption / decryption functions are? And it is worth using them to encrypt important data.

function encode($unencoded, $key)
    {
        $string = base64_encode($unencoded);

        $arr = array();
        $x = 0;
        while($x++ < strlen($string))
        {
            $arr[$x-1] = md5(md5($key.$string[$x-1]).$key);
            $newstr = $newstr.$arr[$x-1][3].$arr[$x-1][6].$arr[$x-1][1].$arr[$x-1][2];
        }
        return $newstr;
    }

    function decode($encoded, $key)
    {
        $strofsym = "qwertyuiopasdfghjklzxcvbnm1234567890QWERTYUIOPASDFGHJKLZXCVBNM=";
        $x = 0;
        while($x++ <= strlen($strofsym))
        {
            $tmp = md5(md5($key.$strofsym[$x-1]).$key);
            $encoded = str_replace($tmp[3].$tmp[6].$tmp[1].$tmp[2], $strofsym[$x-1], $encoded);
        }
        return base64_decode($encoded);
    }

If they are bad, then please throw an alternative. Please do not offer mcrypt, it is already outdated ...

Answer 1

But what about php.net/manual/ru/function.openssl-encrypt.php ?

Answer 2

I don't understand how this can even work if md5() is a hashing function.