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.
This youtube link give a good introduction to using weld-on 4.
Each card is made up from 3 layers of 2mm acrylic, 120mm X 75mm.
The middle layer is done as two C shaped bits that almost meet up.
The outer layers have a deep etching line down the middle that helps it snap.
Inside the biscuit is two bits of red card, the top layer has a challenge code, the bottom layer has the responce code.
Here is a link to my SVG that give you the size and shape needed.