Proof of work

Nonoutsourceable Scratch-Off Puzzles to Discourage Bitcoin Mining Coalitions

An implicit goal of Bitcoin’s reward structure is to diffuse network influence over a diverse, decentralized population of individual participants. Indeed, Bitcoin’s security claims rely on no single entity wielding a sufficiently large portion of the networks overall computational power. Unfortunately, rather than participating independently, most Bitcoin min- ers join coalitions called mining pools in […]

Cuckoo Cycle: a graph-theoretic proof-of-work system


We introduce the first graph-theoretic proof-of-work system, based on finding cycles in large random graphs. Such problems are arbitrarily scalable and trivially verifiable. Our implementation uses 1 bit per edge, and up to 1 bit per node. We hypothesize that using significantly less causes superlinear slowdown.