KraymiKrons

function myfunc($text){
	$text = utf8_encode($text);

	$buffer = [];
	foreach(mb_str_split($text) as $v)
		$buffer[] = ord($v);

	for ($i = count($buffer)-2; $i >= 0; $i--)
		$buffer[$i] ^= $buffer[$i+1];

	$buffer[count($buffer) - 1] ^= $buffer[0];

	return implode(array_map("dec2hexbyte", $buffer));
}

function dec2hexbyte($number){
	$hexval = dechex($number);
	if(mb_strlen($hexval) == 1)
		$hexval = "0".$hexval;
    return mb_strtoupper($hexval);
}


$text = "my text";
echo myfunc($text);