Tokens signed with RSA
Trade-off: The signature is checked with a public key, and the private key stays safe. Downside: generating and distributing keys is done by hand.
A meal planner for a family, my final-year project.

A professor wanted a meal planner for his family. The starting specification was fixed: we had to follow it. After that, the freedom to innovate beyond it.
Trade-off: The signature is checked with a public key, and the private key stays safe. Downside: generating and distributing keys is done by hand.
Trade-off: The HTTPS connection goes through a certificate imported by hand. Downside: a manual step to repeat on every machine.
Getting four people's ideas to converge, and meeting the delivery deadlines.
A good result, and a good team experience.