This is for pedagogical purposes. Please do not cypher actually important messages with this.
Anyway I think it can bring with little ones, and adults alike, interesting conversations around :
- secrecy
- privacy
- cryptography as counter-power
- mathematics, starting with modulo
- the duration a message can stay undecipherable and thus the kind of message to share
- computational complexity, how many permutations are available
… and a lot more!
That would make sense, if it’s educational then it’s probably used to teach about the Caesar/shift cipher