Thanks for pointing out the use of Hashcache. Since there are many projects apparently using this name, for anybody else like me wanting to search it up, it's

Thanks for pointing out the use of Hashcache. Since there are many projects apparently using this name, for anybody else like me wanting to search it up, it's the proof of work one: https://en.wikipedia.org/wiki/Hashcash https://en.wikipedia.org/wiki/Hashcash