soulbound token claims

From FIPs P2P Marketplace

Implementation must contain a set of claims using beezk, already described as

• provenance claim which attests for a proof of origin of a NFT metadata
• publisher or issuer claim which attests for proof of originator
• wholesaler claim which attests for a proof of allowed or certified wholesaler

In gnark circuits standard library, we get can translate this to:

• Provenance claim must be implemented with a merkle proof verification
• Issuer claim must be implemented with a merkle proof verification
• Wholesaler claim must be implemented with a zk snark verification as in Is this wholesaler/marketplace certified to sell my NFTs? yes or no? without disclosing which wholesaler are or not certified.

Claims

We can define a claim, which must be referenced in the soulbound token, using circuits:

Claim circuits

• disable(address, claim_type, claim_signature_ref)
• require(address, claim_type, claim_signature_ref)
• grant(address, claim_type, claim_signature_ref)
• revoke(address, claim_type, claim_signature_ref)

Examples

Alice SBT has references stored in Swarm with ZK signatures claims for an Issuer actor:

• disable(0x, 'VIP members', hash value in hex): Disables VIP members claim
• require(0x, 'DAO members', hash value in hex): Requires the DAO members claim
• grant(0x, 'Minting access to NFT contract', hash value in hex): Grants minting access to smart contract

An NFT has a SBT with Provenance claims:

• require(0x, 'Certified Marketplace members', hash value in hex): Requires the Certified Marketplace members claim
• require(0x, 'NFT Owners', hash value in hex): Requires the NFT Ownership members claim
• grant(0x, 'NFT metadata verification', hash value in hex): Grants NFT token address a verified metadata verification reference.

A NFT marketplace has a smart contract with a verifier for NFT metadata verification:

• require(0x, 'NFT metadata verification', hash value in hex): Requires the NFT metadata verification claim

Note: Circuit implementation requires further investigation

===

beezk boilerplate features

• Write, debug and compile gnark circuits using Go tooling
• Write, debug and compile solidity using Hardhat
• Output gnark circuit to solidity

Project structure

/build

Circuits are compiled inside build directory, where a solidity artifact is created.

/circuits - gnark circuits

There are two examples from gnark library, the default cubic equation circuit and a MiMC circuit called age18orOlder. Additional helper functions are EdDSA signatures, Merkle proofs and zk-SNARK verifier

/contracts

Solidity contracts

/test

Solidity tests

gnark compilation npm command

npm run compile:circuit

Compiles build/contract/main.go, outputs a proof and verifier. Builds a Solidity contract verifier ready to use.

Maintainers

• @molekilla

License

MIT