Quote: "well currently, I think only E F R C shift are used for the most part the rest are waiting to be added I thought?."
think you may have missed WASD there?
you can use my method of obtaining a passcode using entites though (some commercial games simply have the code on pieces of paper etc rather than require direct input and then once you collect the full code it'll let you pass)
you could use a similar system, maybe just have the player collect 3 or so security cards before he can pass.
http://fpscrforum.thegamecreators.com/?m=forum_view&t=207801&b=2&msg=2479693#m2479693
life's one big game
windows vista ultimate
i5 @3.3ghz, 4gb ram, geforce gtx460, directx 11