I finished off my computer science unit with a breakout activity that I thought went very well. I broke each class into four-person teams, and game each of them a locked box. The only clue on the box was a long string of 0s and 1s I attached with a label maker. The students eventually figured out they need to translate the binary into ASCII, which gave them the combination to the lock (the first class actually figured out they could get the contents out of the cheap Harbor Freight box without actually opening the lock. I fixed this later by packing more stuff into it!). Inside the box was a hard drive, with a sticky note challenging them to guess the password. It also contained a decoding wheel, which we’d used doing ciphers earlier. The students installed the drive into a computer (computers were conveniently stashed nearby) and attached all the peripherals. When they boot it, they were met with a password screen, and had to guess. This was the trickiest part, since all the groups were trying to decode random things to find a password. I’d hoped they’d get my earlier hint and try to actually guess common passwords, which they eventually did.
The only file visible on the computer screen was a secrets.txt file, which contained a ciphered text and a cryptic clue the students needed to google for the key. This went very smoothly, and almost all groups were able to decode the Vigenere cipher pretty quickly (a victory for me, since I’d tried unsuccessfully to teach it in the past!). The cipher instructed them to find another searchable piece of information, and deliver it and a flower to the front desk. I was just curious to see how the groups would handle the flower. Some picked one outside, one group brought a flower-shaped pen. No one thought just to draw one. Once everything was delivered, each group member got their 3D-printed “I Survived Computer Science” medal.
I got lucky in that the activity took up about the right amount of time. The last group finished with about ten minutes left in the hour-fifteen minute class. That left just a bit of time for clean-up! When I surveyed the students, later, they said this was one of their favorite parts of the class, so I’ll definitely be trying it again.