Hi,
I can't see any attachment regarding the top marking. Can you please provide the top marking.
Altera has its authorized distributor to sale Intel devices. If you got the devices from formal distributors, you shouldn’t worry on the device authenticity/validity as the devices must be valid units. Otherwise, we do not ensure the device quality and do not provide the further service. You may find the authorized distributor list from the link below:
https://www.intel.com/content/www/us/en/programmable/buy.html
Regards,
Nazrul Naim