To insure that only those that had the right to be in our R&D facilities, we used electronic keys- 30+ years ago. Moreover, the codes changed, based upon the hour of the day. That way those who should not have been in the lab after hours couldn’t be. That was one way we kept our technology to ourselves. Of course, back then there were no USB keys that you could plug into a computer and walk away with secrets. But, you could make a floppy. Somehow, we managed to keep our data smaller back then, too- so a lot could disappear on that floppy (or two or three).