> For the complete documentation index, see [llms.txt](https://tokens-economy.gitbook.io/consensus/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://tokens-economy.gitbook.io/consensus/chain-based-proof-of-capacity-space/proof-of-space-poc.md).

# Proof of Space (PoC)

(PoSpace), also called proof-of-capacity (PoC) is a means of showing that one has a legitimate interest in a service (such as sending an email) by allocating a non-trivial amount of memory or disk space to solve a challenge presented by the service provider.

## Used in

* [Burstcoin](https://hackernoon.com/burst-part-3-proof-of-capacity-the-green-alternative-8e2651211671)
* Chia
* SpaceMint

## Pros

* Efficient , cheap, distributed

## Cons

## Read more

[Wikipedia](https://en.wikipedia.org/wiki/Proof-of-space)