Agree with Sunfish entirely. If introduced it would be yet another cost borne by the user (pilots). In any case it is totally unnecessary and like purchasing a hammer to crack an egg. Simply putting the gate code airside as is done at many country airports is all that is required.In fact with a bit of imagination it could even be on the public side too in case you forget to write it down.eg "for access enter the local PAL freq" or area,ctaf,NDB etc and even rotate them often.Any pilot will know what it is but the general public not a clue.