KringleCon and other InfoSec Writeups

I've decided to try to create a more thorough write-up of KringleCon / Frost Fest this year, but I also don't want to make this unreadably long. So if you're just after the answers, ignore all of the hidden text below and jump ahead to whatever you want to read. If you're after a bit more depth, in addition to the answers, I've documented: the missteps I took trying to figure it out, even all those that lead no where. Mostly because I forget how tough I find stuff and then feel bad whenever I struggle, or I read other people's write-ups and feel intimidated by how easy everything seems to be for them. the wider picture: what the challenge teaches us and how it relates to the real world. This will also contain links to additional sources that may be helpful but don't really fit in the challenge. I think this might be helpful for people outside cybersecurity or for when I half-remember something and want to reference it later. ...