# Proof of Location

Proof of Location is a technology that enables a device's physical location coordinates to be broadcast to the blockchain in a way that other devices can rely on the location data without having to trust the broadcasting device.

Position-dependent applications include supply chain, parametric insurance, KYC/AML verification, or even consumer transactions. E.g, an online store might need to prove that an item has been delivered to you so that the smart contract can automatically trigger a payment from your wallet.

Today’s geo-location tools are great for determining the location of a device, but cannot offer reliable and trusted location verification services. They are uni-directional and un-encrypted, which makes it problematic to rely on GPS for smart contracts that need to execute when spatial parameters are met. Dynamic Proof of Location empowers a permission-less and autonomous network of radio beacons that can offer secure location verification services through time synchronization in a decentralized manner.

### Challenges

* Difficult to implements

## Used in

* The [FOAM](https://www.foam.space/) Proof of Location protocol empowers a permission-less and autonomous network of radio beacons that can offer secure location services independent of external centralized sources such as GPS through time synchronization. The will deliver a hardware-based solution and have miners, Foam nodes provide geo-triangulation combined with a verified timestamp.
*  XY Findables sold more than 100K devices and [XYO](https://xyo.network/)  plan to roll out a firmware upgrade to enable all the owners of these devices  to become nodes/‘sentinels’ in a ‘Proof of Origin’ consensus.
* [Platin](https://platin.io/) is using a Proof of Location protocol on their own blockchain, called the Plexus™, [Platin](https://platin.io/) makes it simple to verify a location claim. 
* [http://animist.io](http://animist.io/) is an open source Bluetooth server/beacon that lets Ethereum micro-computer clients proximity-detect mobile devices and write information about their location to a smart contract.

## Pros

* Trustless: Byzantine fault tolerant clock synchronization
* Independent: Does not rely on GPS
* Open: Anyone can utilize the network or offer utility services
* Accountable: Economics structured to ensure honest behavior, verified with fraud proofs
* Incentivized: Service providers remunerated for extending localization and verification zones

## read more

* [Using Blockchain for Peer-to-Peer Proof-of-Location (research whitepaper)](https://arxiv.org/pdf/1607.00174v2.pdf)
* [FOAM blog](https://blog.foam.space/introduction-to-proof-of-location-6b4c77928022)
* [FOAM](https://foam.space/)
* [Medium Foam vs Platin (sponsored)](https://hackernoon.com/meet-platins-proof-of-location-a-secure-and-verifiable-location-consensus-protocol-336528626e7e)