- substr: documentation ( source)
- bin2hex: documentation ( source)
- time: documentation ( source)
- pack: documentation ( source)
- random_bytes: documentation ( source)
<?php
$a = pack('N', time());
$b = pack('N', substr(time(), 2, 8));
$c = random_bytes(2);
$d = random_bytes(2);
echo bin2hex($a . $b . $c . $d).PHP_EOL;
echo time();