Authentication codes are.
WaPo and numerous other sources have reported that the war plans and authentication codes are inside the president's briefcase in the US. I don't know how they do things in Russia, since I would assume you can be shot for questioning if Fearless Leader is in fact Fearless Leader, but around here the president is expected to confirm his identity to NORAD before launching a strike. This is why the briefcase is with him at all times, since he could be looking at minutes to respond in the event of an SLBM strike fired from off the East Coast.