Useful Proof of Work (UPoW)

Useful Proof of Work (UPoW) is a label for blockchain consensus designs in which miners' computing effort produces a useful result as well as securing the network. Classic proof of work, as used by Bitcoin, has miners repeatedly run a hash function until they find a valid result; that work protects the chain but has no other use, which critics see as wasted energy. UPoW proposals try to swap the hash puzzle for work such as scientific calculation, searching for special prime numbers or training models. The hard part is that the work must be easy to check, hard to fake and steady in difficulty, which few real-world tasks are. The term is not a single standard, and different projects use it for different designs, so their own documents are the best guide. Also see mining and consensus mechanism.