Anthony, I'd assume from your use of the word "Proximity" that your state ID cards have got RFID chips in them. In this case, just find a suitable RFID reader and feed it into a computer system of some kind, an Arduino should be adequate but you could use a Raspberry Pi or a PC.You could store the ID's that are permitted access and if it reads a match then it will allow access to the safe or whatever. You'd obviously need a bit of programming expertise for this but I'm assuming (since you posed the question on a forum like this) that you'd have some....it should not be difficult. Once you have a master ID (Yours) you could use that to enable you to have "superuser" access to add and delete cards to the access permitted list.If anyone with a state ID is to be allowed access, you'd probably find that those ID cards have a fixed prefix or some detail in the number, and use that to prohibit the use of other ID cards, and you could log and download a list of cards that have accessed the system.Google "RFID Reader" and you'll get a wealth of possibilities. You can get fairly cheap USB types that would plug into a PC or RasPi. There are several variants of RFID so make sure you get the right one. ST Microelectronics are fairly active in the RFID field and may have somethiign that does what you want.Once you can read the cards, you're limited by your imagination as to what you can do....
