Proof of Location 101
What is Proof of Location?
Long Answer: For an in-depth explanation, refer to our Arxiv paper.
Short Answer: Proof of Location (PoL) enables any DePIN node to prove its geographical location. It is a Fundamental Infrastructure Proof System (FIPS) that maps the location of DePIN nodes within a confidence region.
PoL is a software product and requires no additional hardware. This is a huge enabler for robustness against adversaries. It works by triangulation over internet pings made by many challenger nodes to a prover node looking to prove its location. Researchers at Witness Chain innovated Byzantine Fortified Trigonometry (BFT) to make PoL Byzantine fault resistant in its functioning.
Location is one of the most crucial physical attributes of physical infrastructure nodes. Location information can improve the utility of the network by bringing transparency to the state of physical decentralisation. More geographical spread will lead to higher coverage of certain networks.
Distributed file storage systems rely on nodes spread across different geographical locations for protecting data against the potential fallout of regional catastrophic disasters. Decentralized wireless network solutions, aim for deploying nodes in diverse locations to achieve global coverage. Moreover, certain DeFi applications demand precise location information to adhere to specific constraints and regulatory requirements. Proof of location will also find it’s utility alongside Proof of Bandwidth to help identify is any asset has been virtualised.
The principle of decentralization further amplifies the need for geographical diversity; the more geographically varied a network is, the harder it becomes to censor or control it. However, the trustless nature of the blockchain platform also poses a set of new challenges, for example, nodes can use VPN to spoof its location. The PoL protocol can detect such behavior and verify location without relying on any centralized trust.. Read on to learn how.
How Does PoL Work?
PoL involves two main parties: Challengers and Provers.
- Provers: Any DePIN node that wants to prove its location.
- Challengers: Responsible for sending signals (internet pings) to the prover node. By analyzing the time it takes for these signals to reach the prover node, the location of the prover can be triangulated.
The output of the protocol is the uncertainty of the prover, which is the maximum deviation of the claimed location from the actual location of the prover. The protocol begins with a measurement phase, where all challengers generate data packets, signing them with their private keys (their associated public keys are made public on the blockchain). These challengers dispatch a ping packet to the prover, who immediately signs and sends back the received packet. This process is repeated to measure the minimum round-trip time (RTT) between each challenger and the prover. Utilizing a robust delay-to-distance function generated by the proof of Internet geometry protocol (during a one-time setup phase), they estimate the distance to the prover and report the measurements.
This system works best when multiple challengers are in similar geographic areas as the prover. In the Phase 1 release for PoL, EigenLayer operators act as challengers, covering geographically diverse locations.
Why is PoL Needed?
Verification is essential for establishing physical trust, which is the foundation for the financialization of DePIN assets and enabling financial contracts on these assets. This is how a decentralized machine economy begins.
PoL verifies one of the most fundamental physical attributes of any machine: location. Here’s why location information is crucial:
- Physical Trust: Establishing physical trust paves the way for financial contracts and the broader financialization of DePIN assets.
- Decentralization Measure: Diversity in the locations of DePIN nodes is a measure of the actual decentralization of the DePIN network.
- Data Security Compliance: Ensures compliance with data security regulations (e.g., GDPR) wherever data is stored or sent to the DePIN node.
- Resource Pricing: Verified location data helps communities better price their network or benefit from price arbitrage for resources, as costs and prices of resources vary by location.
Stay tuned for more updates as we continue to develop and refine our Proof of Location, and other proof systems. For a deeper dive, check out our technical publications.
