Welcome back, chain chasers! Nora here, with my firewall cape on and encryption goggles at max zoom. Today, we’re hashing out one of the bedrock technologies in crypto: SHA-256. That’s right—this little mathematical marvel, cooked up by the NSA of all places, now underpins the very thing it might’ve once tried to control—Bitcoin.

But before you start yelling "PRISM!" into your webcam mic, be sure to study up by reading The NSA and Bitcoin: Origins of the SHA-256 Hashing Algorithm. Once you’ve brushed up on the basics, come back and see if you can ace the quiz. After all, the multi-chain future isn’t going to debug itself.