A few month ago, I got my new 3D Printer. As a Kickstarter project, it came as half-baked product - its firmware topped with many annoying bugs. In hope to fix some of them, I went to look into the firmware, but alas - it was encrypted with some sort of substitution cipher. In this talk I will show you how I used some data science, statistics, ARM architecture knowledge and much guesswork to defeat the encryption of the firmware. We will see some Python code and I will walk through some IDA scripts I built especially for this mission. Let the firmware's secrets reveal themselves!