Would you, in real life, ever want to try smuggling drugs through a military base? How about Groom Lake?
Juni, a former Commander of the LSF, more or less states the only thing she knows about Zone 21 is that there is a jump gate in the heart of Zone 21 (presumably a hasty or informal reference, given the infocard differentiates the minefield from Alaska/Zone 21 itself).
So, I doubt that even most of the Navy/LSF would have the codes, unless they were given them by High Command or what is probably a hand picked group of elite guard sworn to secrecy, if security around it is anything like the campaign or it's counterpart in A51 indicates.