Here is a prototype I made (with Berlin spy museum in mind as future client).
It's a simple DIY encryption device made using conuctive tape.

Decrypting works like this:
Rotate the paper disk into position, matching the encrypted letter to the black triangle. Then press the button provided with the encrypted letter. An LED will illuminate the decrypted letter. Encrypting works the same but reverse. How you make the connections is your "key".

#stemeducation #mint #fedilz #diy #encryption