What is Commun Platform

Commun Platfrom is a platform for distributing and verifying proof of visit. We use off-chain signatures and proximity wireless communication to provide proof of visit(PoV) that can be leveraged on-chain with fraud and tamper-resistance.

Problem

How do you present PoV for your users? Do you use GPS or QR codes?

GPS is a good technology for knowing your location, but not for knowing the location of others.

If you place a unique QR code at a location, anyone who reads the QR code will have visited the location. However, QR codes can be easily duplicated and spread over the Internet now that everyone has a camera.

These are not trustless off-chain. Because GPS can be easily tampered with and QR codes are processed in a black box, a server owned by the company. This is why it is difficult to utilize them in smart smart contracts where incentives are involved.

Solution

This is achieved through proximity communication between the visitor and the device we provided and off-chain ECDSA signing. We call the device a spot device.

The spot device generates the ECDSA key in a secure module inside the device. The ECDSA private key held by the spot device cannot be retrieved from the outside. In other words, only the spot device can generate signatures with its ECDSA key. In addition, the spot device sends the spot signature to the visitor via proximity communication, but the spot device is not connected to the network. Therefore, it is NOT possible to receive spot signature from a spot device via the Internet. The above makes it possible to realize a signature that can only be received by those that have visited the spot device.

If we write to the on-chain based on the verification result of this signature, we can obtain a PoV that can be utilized on the on-chain.