<?php
function Xor_String($text,$key) {
    $i = 0;
    $encrypted = '';
    foreach (str_split($text) as $char) {
        $encrypted .= chr(ord($char) ^ ord($key{$i++ % strlen($key)}));
    }
    return $encrypted;
}
    $text = "SomeText";
    $key = "123";
    $encrypted = Xor_String($text,$key);
    $decrypted = Xor_String($encrypted,$key);
    echo($encrypted);
    echo($decrypted);
?>

 

 

test