I posted about this elsewhere in this thread but you might be interested in this paper: https://eprint.iacr.org/2021/1379 https://eprint.iacr.org/2021/1379 It

I posted about this elsewhere in this thread but you might be interested in this paper: https://eprint.iacr.org/2021/1379 https://eprint.iacr.org/2021/1379 It gets about 50% efficiency compared to the current state of the art for the problem space without compromising any of the security properties that make for a good PoW algorithm. Generally I'm not a fan of PoW and prefer internal resource based consensus algorithms but PoUW algorithms seem rather interesting. I think we are reaching a point of maturity in the space that'll allow these types of self-securing service marketplaces (which really is what PoUW is) to reach their logical conclusion.