https://www.extremetech.com/internet/268263-f-secure-hack-unlocks-millions-of-hotel-rooms-with-handheld-device
origin - https://www.pipiscrew.com/2018/04/f-secure-hack-can-unlock-millions-of-hotel-rooms-with-handheld-device/ f-secure-hack-can-unlock-millions-of-hotel-rooms-with-handheld-device