[eluser]searain[/eluser]
"encode" the value before pass
$value = str_replace('=', '-', str_replace('/', '_', base64_encode($value)));
"decode" the value after receive
$value = base64_decode(str_replace('-', '=', str_replace('_', '/', $value)));
You can write a helper like this.
I don't do this on the values input by the end users.
And after receive the value, I validate the value again.