Uncrackable? My first reaction was, yeah, right, sure. Claiming you have uncrackable code is like waving a red flag in front all the computer science students in the world. They are going to be all over you like flies on shit and later next week we'll have somebody presenting a paper on how they managed to crack your uncrackable code.
But I watched the video, and Senor Hart, he may know what he is talking about. The idea is all of the components in the bomb would be 'smart', and they would all have the capability of sensing the fluctuations in the radiation that the nuclear part of the bomb was producing. When the bomb is originally assembled, the components all measure the flux, and they all talk to each other and exchange the nuclear bomb component equivalent of secret handshakes and then they go to sleep.
Now if anyone wants to set off the bomb, all these components will wake up, measure the radiation flux and talk to their fellow components, and if everyone remembers the secret handshake, and the flux has the same characteristics, then we're good to go and the bomb can be detonated. If anyone finds anything that is not to their satisfaction, that component will refuse to cooperate and the bomb will not go off.
If no one every takes the bomb apart, then the bomb can go boom. If someone steals the whole bomb, the bomb can go boom. If someone steals a pile of components from previously assembled bombs and tries to put together their own bomb, the bomb no go boom. So I'm thinking one smart component needs to be removed from the bomb and kept separate. But you need to remember which bomb it goes to, and in the fog of war, are we going to be able to keep that straight?
Might be better if we made these components uncooperative so the bomb doesn't go off no matter what. I mean look what smart bombs did for Dark Star.