Shannon Phygital

Inspiration

There are a number of projects that introduce NFC-tagged items to the blockchain, but none of them offer privacy guarantees. We came up with the idea to build a privacy-preserving phygital Web3 platform before we learned that Aleo will giveaway caps with NFC tags during Aleo Hack. These tags are only mintable on a fully public Ethereum. We realize that it’s time to bring private NFC tags to Ethereum. This is how “Shannon Phygital” was born!

“Shannon Phygital” is tribute to prominent mathematician and computer scientist Claude Shannon, who laid the foundation of modern cryptography.

What it does

We have built Shannon Phygital as an Aleo dApp that can read an NFC tag, create a private record on the blockchain, which represents physical ownership of an Aleo cap. This guarantees that you own an authentic Aleo cap. But in contrast to existing solutions, all your ownership information is private by default.

This still leaves you an opportunity to show off your swag and flex on other anons publicly by disclosing the item that you have.

All this experience is packed as a slick progressive web app with an embedded wallet. No need to install external wallets and worry about seed phrases. Moreover, we top up your embedded wallet with some credits automatically to get you started using Aleo.

We don’t compromise on security. Your private keys never leave your device, and we currently work on protecting them using a secure enclave and biometric authentication of your smartphone.

Finally, we plan to build this product as an open source platform. So don’t hesitate to reach us to drop your own streetwear collection or build new awesome features!

Shannon Phygital dApp has the following functionality:

Login with Twitter
Generate an embedded wallet and automatically top-up it (the private key never leaves the app and will be later secured by WebAuthn)
Scan an NFC tag
Register an NFC tag of a piece of clothing by minting a private record
Transfer ownership to another user (not yet available on UI, only through contract call)
Publicly disclose ownership (not yet available on UI, only through contract call)
Add NFC tags by a manufacturer (not yet available on UI, only through contract call)

Use cases

There are several use cases that Shannon Phygital unlocks:

Private-by-default phygital ownership and experience. Prove ownership and build awesome experiences while remaining fully private. Make holders who wear your merch to receive special perks during IRL events or reward your fans with tokens and content without compromising their privacy.
Flex your swag if you want to. Users are in-control of their privacy and can reveal to everyone that they owned a certain piece of garment. Think of a celebrity like Vitalik Buterin proving that he owned an Aleo cap #888, making it a sought after collectible!
Solve the problem of counterfeit fashion apparel on the secondhand market. The global apparel secondhand market was estimated to be worth 211 billion U.S. dollars in 2023. Shannon Phygital guarantees authenticity of the piece of clothing without relying on any oracles or centralized storages. On primary and secondary markets, a seller transfers an Ownership Record to the buyer to guarantee authenticity. Because there is one-to-one correspondence between an NFC chip and a piece of apparel, a seller cannot sell counterfeit items.

How we built it

We built Shannon Phygital as a PWA Aleo dApp with the help of Leo, React, Node.js and deployed it to Aleo Testnet and Digital Ocean VPS.

Challenges we ran into

The main challenge was to scan an NFC tag and execute Aleo transactions from a PWA. Due to the limitations of the Web NFC API, the app currently works only on Android devices. Executing Aleo transactions from a PWA also proved to be challenging because of the Webview and limited resources (e.g. memory).