I put blockchain in the basket of amazing and exciting tech. I would love to play with more. A bit like Amazon Echo. I think about what cool things I would build with it if I had time to do so. But I am still not sure how it would be applied practically in Moodle.
Verifying certificates and anti-plagiarism look like candidates. Perhaps providing conditional access to courses and activities across multiple and unconnected Moodle sites? Kind of like a global pre-requisite system.