Glossary
Proof of Space (PoSpace)
A consensus mechanism in which participants prove they have reserved unused disk storage instead of spending computation or capital, pitched as a low-energy alternative to proof of work.
Proof of space is a consensus mechanism in which participants prove they have dedicated unused disk storage rather than computation or stake. Farmers pre-fill hard drives with cryptographic data called plots; when the network broadcasts a challenge, whoever holds a plot value closest to it wins the right to create the next block. Because reading a plot costs almost no electricity, proof of space is marketed as a greener alternative to proof of work.
Chia is the best-known network built on it, usually pairing proof of space with proof of time — a verifiable delay function — to resist grinding attacks. Critics note that the one-time plotting phase is hardware-intensive, and that demand for cheap capacity can still drive e-waste and storage centralization.