I want to teach some people about crypto basics, and one of the topic will be key exchange with a public and private keys.
The audience is made of people working in InfoSec, but mostly junior fresh out of school.
I am looking for a visual/experimental way to show how we can achieve key exchange with both parties having a public/private elements.
I like it, but it only shows the use of 1 secret key, there's no concept of public key. Also, color may not be as intuitive as I like because people tend to think you can unmix (even if we made the hypothesis we can't.) And a real-world experiment would probably get messy.
Is there another example that would relay on 2 elements from each sides?
I made some attempts with pieces of paper, but alas, nothing came out. I would need a transformation that can be done with 1 piece of paper, and that can only be undone with another. Perhaps someone have a bright idea here.
PS: I introduce the concept of public/private key with the padlock/key analogy, which is very good. However this just depicts a 1way transfert of data, it is not a key exchange.