this is very simple encryption using strtr
the higher the level the more encrypted it becomes but is not unbreakable
this will handle messages up to 999 characters long
for best incryption use strlen($message) as levels argument in function call
$message="incrypt this message";
function encrypt($message,$levels,$skip,$key='c 5x1ag9e0wyzjbl3dmkh82vu6opqir4sn7tf')
{
for($i=0;$i<$levels;$i++)
{
$len=strlen($message)-($i*2);
$key=substr($key,$skip).substr($key,0,$skip);
$message=strtr(substr($message,0,strlen($message)-$i),"abcdefghijklmnopqrstuvwxyz 1234567890",$key).substr($message,strlen($message)-$i);
}
return $message.str_pad($levels,3,"0",STR_PAD_LEFT).str_pad($skip,2,"0",STR_PAD_LEFT);
}
function decrypt($message,$key='c 5x1ag9e0wyzjbl3dmkh82vu6opqir4sn7tf')
{
$skip=substr($message,-2,2);
$levels=substr($message,-5,3);
$message=substr($message,0,-5);
for($i=0;$i<$levels+1;$i++)
$key=substr($key,$skip).substr($key,0,$skip);
for($i=0;$i<$levels;$i++)
{
$key=substr($key,-$skip).substr($key,0,37-$skip);
$message=strtr(substr($message,0,strlen($message)-($levels-1-$i)),$key,"abcdefghijklmnopqrstuvwxyz 1234567890").substr($message,strlen($message)-($levels-1-$i));
}
return $message;
}
$output=encrypt($message,strlen($message),5);
echo "<br>output = ".$output."<br>";
echo "<br>".decrypt($output);
