I am trying to learn how to send data from a webpage written in php that a person types in, to be encrypted when they click send, and to arrive in an email encrypted. My php hosting does NOT have Mcrypt and it wont be possible to get it.

However I did come up with a script that on the face 'seems' to work, but damned if I can get it to show me the encrypted data, my knowledge of php seems to short still to make it want to show me $result at the different stages? Or maybe I am missing something else?

Anyways here is the original script I obtained. I made a separate notation for $string = "hello world" and $key = "goodbye"

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

<?php
function Encrypt($string, $key)
{
$result = '';
for($i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)+ord($keychar));
$result.=$char;
}
return $result;
}

function Decrypt($string, $key)
{
$result = '';
for($i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)-ord($keychar));
$result.=$char;
}
return $result;
}
?>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is the actual code I am trying after my edits:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

<?php

$string = "hello world";
$key = "goodbye";

function Encrypt($string, $key)
{
$result = '';
for($i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)+ord($keychar));
$result.=$char;
}
return $result;
}

echo $result;

function Decrypt($string, $key)
{
$result = '';
for($i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)-ord($keychar));
$result.=$char;
}
return $result;
}
echo $result;
?>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This does not need to be the mona lisa, aka DES or 256 bit encryption of some sort... just needs to be able to encrypt in a fair way, and decrypt as well. If anyone can help me I would love you to pieces. This is for my self educational efforts to learn more about php and security related aspects (Imma security freak after all)