I solved @robot__dreams first Bitcoin-flavored cryptography challenge (https://gist.github.com/robot-dreams/669c13bc724fdeb9af8460c9b64d5665) with the help of @kalle Schnorr Basics explainer (https://popeller.io/schnorr-basics).

Here's a write-up (and spoiler).

https://b10c.me/blog/009-schnorr-nonce-reuse-challenge/