ETH-ernet

Problem Statement

ETHernet transforms ordinary Wi-Fi into a crypto-native network. After facing the struggle of wifi at the hackathon, we decided to solve this problem with the hardware we had to enable users connect, sign in with Ethereum, and instantly choose between buying a data pack or paying-as-they-go with x402 micropayments.Access is enforced at the router level via OpenWRT, which meters bandwidth and usage per wallet address. Beyond simple payments, the system can integrate reputation checks, POAPs, or discounts for onchain credentials, creating a programmable, permissioned internet layer.The goal is to make connectivity itself a trustless, onchain-powered utility.

Solution

We used OpenWRT as both router and controller, running a captive portal that redirects users to an Express server handling SIWE authentication and payment flows. Payments are processed either through Ethereum transactions for data packs or via x402-style micropayments for continuous metering. Once confirmed, the backend communicates with OpenWRT using ndsctl to whitelist the user’s IP and enforce data/speed rules. The frontend is a simple browser app for login and plan selection, while the backend ties together the Ethereum wallet, payment confirmation, and router control.ChallengesAfter juggling through different hoops of networking, we were ultimately stuck on captive portal being complex for openNDS. Since we were new to it, we had never set reproducible steps to create a working networking environment. Additionally, since our router does not support openWRT we had to run it on a VM via another laptop and rely on router as tether, this added physical complexity and restriction for us.