ERC-1923: zk-SNARK Verifier Registry Standard
Simple Summary
A standard interface for a "Verifier Registry"'" contract, through which all zk-SNARK verification activity can be registered.
Abstract
The following standard allows for the implementation of a standard contract API for the registration of zk-SNARKs ("Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge"), also known as "proofs", "arguments", or "commitments".
TODO: Which functionality is exposed in this standard interface?
Motivation
zk-SNARKs are a promising area of interest for the Ethereum community. Key applications of zk-SNARKs include:
- Private transactions
- Private computations
- Ethereum scaling through proofs of 'bundled' transactions
A standard interface for registering all zk-SNARKs will allow applications to more easily implement private transactions, private contracts, and scaling solutions; and to extract and interpret the limited information which gets emitted during zk-SNARK verifications.
:warning: TODO: Explain the motivation for standardizing a registry, other than simply standardizing the verifier interactions.
⚠️ TODO: Explain the benefits to and perspective of a consumer of information. I.e. the thing that interfaces with the standard verifier registry.
Specification
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
Interface
Rationale
⚠️ TODO: Add Rationale section.
Backwards Compatibility
⚠️ TODO: Add Backwards Compatibility section.
Test Cases
Truffle tests of example implementations are included in this Repo.
⚠️ TODO: Reference specific test cases because there are many currently in the repository.
Implementations
Detailed example implementations and Truffle tests of these example implementations are included in this Repo.
⚠️ TODO: Update referenced verifier registry implementations so that they are ready-to-deploy or reference deployed versions of those implementations. At current, the referenced code specifically states "DO NOT USE THIS IN PRODUCTION".
⚠️ TODO: Provide reference to an implementation which interrogates a standard verifier registry contract that implements this standard.
References
⚠️ TODO: Update references and confirm that each reference is cited (parenthetical documentation not necessary) in the text.
Standards
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ERC-20 Token Standard. ./eip-20.md
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ERC-165 Standard Interface Detection. ./eip-165.md
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ERC-173 Contract Ownership Standard (DRAFT). ./eip-173.md
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ERC-196 Precompiled contracts for addition and scalar multiplication on the elliptic curve alt_bn128. ./eip-196.md
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ERC-197 Precompiled contracts for optimal ate pairing check on the elliptic curve alt_bn128. ./eip-197.md
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Ethereum Name Service (ENS). https://ens.domains
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RFC 2119 Key words for use in RFCs to Indicate Requirement Levels. https://www.ietf.org/rfc/rfc2119.txt
Educational material: zk-SNARKs
- Zcash. What are zk-SNARKs? https://z.cash/technology/zksnarks.html
- Vitalik Buterin. zk-SNARKs: Under the Hood. https://medium.com/@VitalikButerin/zk-snarks-under-the-hood-b33151a013f6
- Christian Reitweissner. zk-SNARKs in a Nutshell. https://blog.ethereum.org/2016/12/05/zksnarks-in-a-nutshell/
- Ben-Sasson, Chiesa, Tromer, et. al. Succinct Non-Interactive Zero Knowledge for a von Neumann Architecture. https://eprint.iacr.org/2013/879.pdf
Notable applications of zk-SNARKs
- EY. Implementation of a business agreement through Token Commitment transactions on the Ethereum mainnet. https://github.com/EYBlockchain/ZKPChallenge
- Zcash. https://z.cash
- Zcash. How Transactions Between Shielded Addresses Work. https://blog.z.cash/zcash-private-transactions/
Notable projects relating to zk-SNARKs
- libsnark: A C++ Library for zk-SNARKs ("project README)". https://github.com/scipr-lab/libsnark
- ZoKrates: Scalable Privacy-Preserving Off-Chain Computations. https://www.ise.tu-berlin.de/fileadmin/fg308/publications/2018/2018_eberhardt_ZoKrates.pdf
- ZoKrates Project Repository. https://github.com/JacobEberhardt/ZoKrates
- Joseph Stockermans. zkSNARKs: Driver's Ed. https://github.com/jstoxrocky/zksnarks_example
- Christian Reitweissner - snarktest.solidity. https://gist.github.com/chriseth/f9be9d9391efc5beb9704255a8e2989d
Notable 'alternatives' to zk-SNARKs - areas of ongoing zero-knowledge proof research
- Vitalik Buterin. STARKs. https://vitalik.ca/general/2017/11/09/starks_part_1.html
- Bu ̈nz, Bootle, Boneh, et. al. Bulletproofs. https://eprint.iacr.org/2017/1066.pdf
- Range Proofs. https://www.cosic.esat.kuleuven.be/ecrypt/provpriv2012/abstracts/canard.pdf
- Apple. Secure Enclaves. https://developer.apple.com/documentation/security/certificate_key_and_trust_services/keys/storing_keys_in_the_secure_enclave
- Intel Software Guard Extensions. https://software.intel.com/en-us/sgx
Copyright
Copyright and related rights waived via CC0.