I was recently made aware of AnyDVD HD, a piece of software that acts as a real-time optical disc decryption engine to bypass DRM protections in DVDs and Blu-ray discs. Apparently it was quite popular in digital piracy circles, but it was shut down in 2024 (likely due to legal issues). This has left it impossible for users to obtain or renew licenses, rendering the software unusable unless you previously had a lifetime license. So I figured why not try to crack it? Surely it wouldn't be too hard.

Well, it ended up being a bit more involved than I anticipated.

We hosted UMDCTF 2025 about a month ago. This time around, our theme was brainrot. I was inspired to write a challenge involving Italian brainrot, and landed on this challenge involving a latent diffusion model and some interesting RNG reversing.

Seeing the popularity of Frank Herbert's Dune in 2024, for UMDCTF we decided to make Dune our theme. But we were left with the question: how should we theme the challenge list to fit a Dune aesthetic? And I had the brilliant idea of making a 3D Dune planet visualization as the challenge interface. It didn't work out as planned, at least not fully...

I wrote this as a companion challenge to attack of the worm for UMDCTF 2024. Except this time it's a patch attack.

once again, the fremen are trying to sabotage the spice harvest and need you to fool the spice harvester's
worm image recognition! this time though, you need to generate a 40x40 patch to add to the image.

I wrote this ML challenge for this year's UMDCTF competition. It's a fun \(L_0\)-constrained adversarial attack problem.

the fremen are trying to sabotage the spice harvest and they need your help! spice harvesters have worm
image recognition technology to know when to avoid a worm attack. luckily for you, a hacker genius got access
to the pixels of the worm image, but you can only change up to 30 pixels of it. can you help the
fremen destroy a spice harvester?

I was invited to judge the cybersecurity category of a hackathon recently. As a judge, I was able to see submissions and judging for all categories, and I saw a dubious choice from the quantum category judges.

I wrote this challenge for the first ever osu!gaming CTF. I wanted a cool adversarial ML challenge with osu! theming, which led me to writing a classifier to detect anime girls in osu! map background images.

This weekend I played in CrewCTF with Babbage Patch Kids. As always, the first thing I did when the CTF started was check the misc category. I found this challenge which appeared to involve classification of random data. Perfectly in my wheelhouse.

The previous owner liked to run his engine inside this house all day long, and before he sold it, he
painted over all the doors. Can you find the right force and offset to crack it?

I spent this weekend playing DEFCON qualifiers, and I found this VM rev challenge that I ended up really enjoying.

Elgyem input the password to his UFO into a neural network, but sadly he lost the password. All he has
left are the network and the output. Can you help Elgyem fly back home?

I wrote this challenge as part of the ML category for UMDCTF 2023. The motivation was to show the possibility of obtaining model input given the associated output for a neural network with exclusively linear activation functions.

I found an old blu-ray disc with a game on it so I decided to dump it, can you find anything
interesting inside of it? 

We are given a game.pkg file containing what is presumably a game. A quick google search of PPU yields some results for PS3 architecture.

I created my own magic wand using an Adafruit BNO055 Accelerometer! I wonder if people will be able
to decipher what spells I cast? (Note: readings were done 10 times per second)

This weekend I played in KalmarCTF with Babbage Patch Kids. I saw this challenge in the misc category and immediately knew: