Identities of the future run on iden3


Introducing – TrustCommunity2 – a community building app for EthCC

Posted by Sacha Saint-Leger on February 25, 2020

Without a powerful sense of community, even the best laws and institutions will remain a dead letter.

— Benjamin Disraeli


Building off our devcon success, we’re excited to announce a second version of our TrustCommunity app.

The emphasis this time around is very much on collaborative decision making and decentralised social validation.

The main features are:

  • Connect with other attendees, and together, build networks of trust around (self-curated) topics

  • Earn Nectar tokens (up to $45k up for grabs at time of writing)

  • Create pseudonymous and self-sovereign identities through the use of BabyJubJub based identities

  • Safeguard privacy through the use of Zero-knowledge proofs

  • Figure out which talks to attend using the built-in EthCC agenda

While very much an initial experiment, we see this as a tool that will help facilitate community self-organisation and self-governance going forward.


Once again we’re teaming up with DeversiFi, which means there’ll be another 650k Nectar tokens up for grabs (around $45k at time of writing).

We’re also happy to announce that we’ve been working closely with with the EthCC team to integrate the official agenda into the app itself.

The hope is that this will make it much easier for attendees to figure out which talks they want to attend.

Same as last time, this app will allow us to showcase a subset of two of our fundamental goals – self-sovereign identities and privacy by design.

This time however, we want to focus less on games, and more on building something that can be of real use to the community.

High-level overview

As before, each attendee will be able to create a BabyJubJub based identity. Once they’ve created their identity, they’ll be able to connect with other identities.

Once connected, attendees will be able to endorse each other for specific topics. Attendees will earn some tokens for each connection, as well as for making endorsements that the rest of the community agrees with.

The idea is to help attendees connect with each other, and together, build networks of trust around topics within the community. You’ll earn some Nectar tokens for taking part, and hopefully make some friends along the way :)

Networks of trust

Upon connecting, participants will be able to assign badges to each other.

Assigning a badge to a participant is equivalent to endorsing that participant for a specific topic / skillset (of your choosing).

Note that topics will be curated by the community, and participants will have the option to select an existing topic or create a new topic of their choice before endorsing another participant.

To incentivize correct endorsements, participants stand to earn more tokens for endorsements that the rest of the community agrees with.

Importantly, the strength of a participant’s endorsements for a specific topic will be weighted by the amount of badges he or she has received for that topic. In sum, the key point here is that your endorsement for a topic carries more weight if others have already endorsed you for that topic.

Through this mechanism, we hope to build networks of trust around topics within the community.

Zero-Knowledge use case

At the end of the game, users will receive a claim from the application server highlighting how well they performed and confirming that their digital identity is indeed part of the network.

They can then use this claim to receive Nectar tokens — the amount subject to how well they performed — without revealing the identity they are using.

They do this by generating a zero-knowledge proof (zkSNARK) that proves that they control the private key of the identity linked to the claim they received from the application server along with the Ethereum address they would like to send the reward to.

For the 🤓 among you, we’ll be using a BabyJubJub elliptic curve for all the signatures.

For more about why BabyJubJub is optimal for zkSNARK operations, see this excellent post. And for our recent EIP on the subject, see here.

Once the proof is sent to the smart contract that has the tokens in question, the reward will be sent to the specified address.

What do we hope to get out of this

In sum, our primary objective is to help attendees build networks of trust around topics within the community, while showcasing some of our technology.

And our secondary objective is for you all to have fun :)

In the long term, we hope the results of this experiment will be useful as a building block towards a more complete self-governance approach.

We’ve written a playbook with more information about how it all works. If you’re going tobe at EthCC, please do check it out.

For now, you can access the official agenda here.

For the latest updates, follow us on twitter or join us on telgram (@trust_comm). 🚀