a replay attack won't work, because every UDP packet data has deadline in nanoseconds. Once this UDP packet reaches the server the deadline will be added to th

a replay attack won't work, because every UDP packet data has deadline in nanoseconds. Once this UDP packet reaches the server the deadline will be added to the blocklist. If an attacker sends the same packet again, the server will check its blocklist for the deadline. It does not matter if the deadline has been reached or not. once the packet reaches the server, the deadline of that packet will be added to the blocklist.