First of all, I'm not a parent nor does my mom allow me having a girlfriend.
Secondly, Hackable safe? I don't think any retailer would provide you a "hackable" one which is contrary to its name but I do have a few tweaks in mind.
You can have Pwngotchi here that I use to practice WiFi sniffing and WPA cracking. This is a Raspberry Pi Zero W-based AI that learns WiFi hacking. My one looks like this
You could adapt a safe lock (servo + latch) controlled via a Pi running Pwnagotchi or similar firmware. You can find youtube tutorials and I can help you too.
On the other hand, I have an even better idea 😋, DIY!
The core idea: use a microcontroller or single-board computer to control a lock, and require some form of hack to unlock it.
Basic Materials:
Raspberry Pi / Arduino / ESP32 (depending on complexity)
Electromagnetic lock or servo lock
Power supply or battery backup (like I said)
Mini Safe / Ammo Box / Toolbox with a latch system (like I said too)
WiFi dongle or Ethernet
Optional: display panel or LEDs for feedback
You can setup demo challenges like a quest board:
Simple Bash Puzzle: A script with logic puzzles.
Upon solving, writes HIGH to GPIO to trigger servo unlock.
SSH Access via Port Knocking: Requires knowledge of port sequences.
Can be taught via online CTFs (HackTheBox)
WiFi Cracking (Ethical 😂): Set up a fake access point.
He must capture the handshake and crack it to get the unlock code.
Puzzle-Driven API Challenge: Host a py Flask server that only returns the unlock code if queried right.
Hidden Messages in Images / Files (Steganography): Clue to unlock stored in a photo on a USB key in the house.
You can ask @ek for such security exploitation ideas, I can help you build the Pi circuit and simulate CTFs.
HIGHto GPIO to trigger servo unlock.