> 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-existence.md).

# Proof of Existence

Proof of Existence is an online service that verifies the existence of computer files as of a specific time via timestamped transactions in the bitcoin blockchain.

## Used in

* Poex.io
* HeroNode
* DragonChain

## Read more

* [Wikipedia](https://en.wikipedia.org/wiki/Proof_of_Existence)