email.php

function num_exchange ($int) {
        $arr = array('W','x','J','y','5','v','l','0','R','M');
        return $arr[$int];
}
function num_rev_exchange ($let) {
        $arr = array('W','x','J','y','5','v','l','0','R','M');
        return array_search($let, $arr);
}
function rand_char_for_n ($n) {
	while($c <= $n) {
		$char .= trim(base64_encode(chr(rand(1,1500))), '=+/');
		$c = strlen($char);
	}
	return substr($char, 0, $n);
}
function encode_email ($email) {
        $str = base64_encode(strrev(base64_encode($email)));
        $stripped = rtrim($str, '=');
        $rand_pos = rand(0, 9);
        return strrev(num_exchange($rand_pos).substr($stripped, 0, $rand_pos).num_exchange((strlen($str) - strlen($stripped))).rand_char_for_n($rand_pos).substr($stripped, $rand_pos));
}
function decode_email ($email) {
		$email = strrev($email);
        $pos_char = num_rev_exchange(substr($email, 0, 1));
        $num_char = num_rev_exchange(substr($email, 1 + $pos_char, 1));
        return base64_decode(strrev(base64_decode(substr($email, 1, $pos_char).substr($email, $pos_char+$pos_char+2).str_repeat('=', $num_char))));
}