Lotus Beacon

Imagine you’re at a bustling event, surrounded by people you don’t know. Wouldn’t it be great if there was a way to seamlessly connect with the right people, and prove those connections in a trustless, verifiable way on Web3? We noticed that the current system uses NFC wristbands and a Web2 server to record greetings. While it’s a fun start, it requires trust in the event organizers: they control the data and could, intentionally or not, alter it. In other words, it’s trustful, not trustless. That's why we developed Lotus Beacon. This is a trustless oracle that captures real-world interactions and brings them onto Web3.

To our knowledge, this is the first oracle that provides on-chain with the physical existence of people and its connection in a trustless manner. As possible use cases of this oracle, we expect - physical existence verification, continuous presence proofs, on-chain identity scoring and gating, and more!

At the event, participants use our app to view profiles of others nearby, helping you find people you’d actually like to meet. When you approach someone and decide to connect, you both tap a button in the app to perform a Physical Handshake. This action uses your smartphones’ Bluetooth to exchange Rolling Proximity Identifiers, or RPIDs, along with signal strength data. Now, what’s special about this? First, privacy. RPIDs change every 10-20 minutes, inspired by the Exposure Notification API. This means your identity isn’t exposed, but your presence is verified. Second, it’s trustless and tamper-proof. The exchange requires mutual confirmation both parties have to agree. This data is then recorded on-chain, so no one can alter it. No more relying on a central server that could be compromised or manipulated. But what about security? We anticipated attacker scenarios. For someone to fake being at the event, they’d need to spoof ever-changing RPIDs and get real participants to unknowingly confirm interactions, a daunting task.

To achieve the idea above, we use Flutter to develop native apps for controlling the smartphones' bluetooth. This native app also supports connect-wallet feature to let users send transactions to blockchain to record their connections with others. Smart contract is written by Solidity and compiled/tested/deployed by Hardhat. Any EVM-compatible chain can be supported. To keep the entire flow trustless, there are no trusted or centralized servers and databases to serve the important logics and data.