Sismo Protocol Contracts

Made by Sismo

There are three core contracts:

• core/AttestationsRegistry.sol: The registry stores all attestations. It is owned by the governance that authorizes/unauthorize issuers to record in it
• core/Attester.sol The standard abstract contract must be inherited by attesters. Attesters are issuers of attestations. They verify user requests and build attestations that will be recorded in the registry
• core/Badges.sol Reads the registry. Stateless Non Transferable Token view of attestations (ERC1155)

It also contains implementations of attester in attesters/:

• HydraS1SimpleAttester.sol: ZK Attester using the Hydra S1 Proving Scheme and the notion of nullifiers. Users must provide a ZK Proof along with their request to generate attestations
• HydraS1AccountboundAttester.sol: Accountbound version of the Simple Hydra S1 Simple Attester. (Users can update at will where the attestation is stored)

A complete overview of the protocol is available in our documentation

Deployed contracts can be found here

First we need to install yarn using curl

sudo apt update
curl --version
sudo apt install curl
curl -sL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt install yarn
yarn --version

Also if you need to upgrade yarn use this guideline

sudo apt install npm
sudo curl --compressed -o- -L https://yarnpkg.com/install.sh | bash

Go on with SISMO installing

yarn

Compile contracts using hardhat

yarn compile

Launch all tests

yarn test

yarn storage-layout

Terminal tab 1

yarn chain

Terminal tab 2

yarn deploy:local

To develop a new attester, you must inherit the core/Attester.sol abstract contract and implement the following functions:

• _verifyRequest(request, proofData): You must implement the user request verification against the proof provided by the user
• buildAttestations(request, proofData): You must build the attestations that will be recorded from a verified user request

Other optional hook functions that can be implemented:

• _beforeRecordAttestations(request, proofData)
• _afterRecordAttestations(request, proofData)

The /attesters/hydra-s1/HydraS1SimpleAttester.sol is a good example of an attester implementing those functions.

A guide is offered in our documentation.

Feel free open a PR with your new attester in /attester!

Distributed under the MIT License.

Please, feel free to open issues, PRs or simply provide feedback!

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