I am setting up an escape-room-esque experience for a group of 11 and 12 year olds. As part of the activity, I'm going to set up an old Mac (likely running Snow Leopard) with a specially-created user account. The desktop will contain an interactive, executable .command shell script that asks the kids to input a series of "passwords" to obtain the code to a safe.

I'm a little concerned that some enterprising child will realize they can open the script in a text editor and just read all the passwords. Making the account boot directly to a console might help, but I'd rather not do that, and there's still a risk someone will know the `nano` command.

How can I make this script as difficult to read as possible?