The Wall – A crossover ETH/IC demo dApp – Next.js, Rust canisters

I believe that crossover Ethereum/Internet Computer dApps could prove to be an explosive combination and so decided to make a simple proof of concept dApp.

Ethereum apps that wants to deliver above and beyond of what is possible on chain often resorts to using regular centralised server solutions. Could off chain functionality instead run on the IC to create a mixed breed of Ethereum/IC apps - truly distributed, serverless and unstoppable?

The Wall is a working demo but could also be used as a template for creating crossover dApps.

I’m exited to get this running on the real IC after the Mercury Genesis. Until then, feel free to clone it and run it locally.

The purpose with The Wall is to try out and showcase a few concepts with regards to building these crossover Ethereum/IC apps. A proof of concept, a demo and possibly a template to use as a starting point for more advanced apps.

Key concepts

  1. Authentication: Can public key cryptography already used by Ethereum be used to login to the IC?
  2. Link eth adresses to IC identities: If owners of eth adresses can easily prove ownership and link that verification with IC identities, that would open up many interesting app possibilites - voting, membership and other various DAO use cases.


The functionality of the app is super simple. Connect Metamask wallet, sign a login message, select a username. Then you can post messages to the wall.

Login details:

  1. User signs a login message using Metamask. The login includes a hashed secret that for the purpose of this demo is set by the app. To add an extra layer of security this secret (password) coud instead be chosen by the user.
  2. App generates the Ed25519KeyIdentity needed to authenticate with IC based on the signature hash.
  3. Message hash and signature is sent to IC where the eth address used to sign the message is recovered and linked to the IC identity.

That’s it! Now, the app can interact securely with IC, and IC has verified knowledge of which eth address the user controls.

∞ FTW!

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wow, this is super cool!

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Awesome ! Now I see a real bridge between the two ecosystems.

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:partying_face: App is now live on IC mainnet!

Try it here :point_right: https://rivyl-6aaaa-aaaaf-qaapq-cai.raw.ic0.app/

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Wow… this is awesome.

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I love this sooo much

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This is badass,

Thanks for sharing the code.

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Awesome thanks for sharing! Great work, super cool to see it actually working :sunglasses:

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Can I suggest adding some functionality that would be interesting to see.
1- How many unique addresses signed on the wall => this will show us how many people are curious about eth and ICP
2- Timestamp of each post => this will show us how active is the wall
3- Total cycles burned => this will give developers an idea how much it cost to make such app

Thanks for great suggestions! I’m not planning to do additional work on the app in the near term but would more than welcome contributions from the community.

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There is a new version of The Wall out. A few features added, updated to latest IC libraries.

New url: https://wall.fmckl.se/

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Great job, guys!
Keep it up!

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