This post will cover this red break cards, the plastic authentication biscuits.
This Youtube of opening of wargames shows the use of the break cards, this is what I used as a reference. The red break cards are often called “Biscuits” but my research shows that the real name is Sealed Authenticator System, but during my work I called then biscuits. It turns out you can’t buy them anywhere, trust me I looked. So I decided to make my own from laser cut plastic.