Wow, I had no idea that this was such an old and already established concept/idea... When I was reading NIP-13 I was like hmm that is nice, simple and elegant solution. Thank you for sharing. My today's Wikipedia free fall will start with Adam.
Discussion
It’s a very elegant idea! Just counting the number of 0 *bits* at the start of the hash. Bitcoin uses a more sophisticated and granular approach by interpreting the difficulty as a 256-bit number. Hashcash’s downside is that it gets less granular for each bit
