Wedding CTF

Hi there, little off topic!

I’m getting married this year and since (hopefully) my coworkers will attend, I want to have a little detail with them.

We work in cyber so I was thinking about a little CTF, maybe with cyberchef involved, but I want to hear your ideas!

The only think you have to have in mind is it should be short to complete and mobile phone doable.

Bonus points if you add the prize to the winner :)

Thank you in advance and happy hacking!