1.) The technology to build a flying car has been around for awhile...you can have one built for a few million dollars...you just can't use it because of the Oil Industry's Monopoly over even the Government's Vehicular Laws, making the use of a non-fuelled vehicle illegal.
2.) Humans are incapabale of making something more intelligent then themselves, as they couldn't comprehend the construction of it...more knowledgeable maybe, but intelligence greater than the creator is impossible.
3.) Most countries have their weapons divisions connected through a VERY secure network, that uses a more advanced encryption method than RSA because it's too easy to crack...RSA has never been cracked in the decades of it's existence, no computer is fast enough to do that without the key code...it would take years.