3. interoperability and standardisation

halo2 is one of many zero-knowledge proof systems in production: our community is keen to support interoperability and standardisation efforts across proof systems.

proof composition

• FRI verifiers written in halo2:
  • maxgillett/halo2-fri-gadget
  • DoHoonKim8/stark-verifier
• halo2 backend for Noir [WIP]
• snark-verifier: aggregation circuit and EVM verifier generator for halo2-KZG proofs
• halo2-solidity-verifier: Solidity verifier generator for halo2 proof with KZG polynomial commitment scheme on BN254

arithmetisation

• plaf: Plonkish Arithmetization Format: a standard format for plonkish circuits that can be reused in components that work with plonkish arithmetization. The current implementation supports the halo2 frontend.
• High Assurance Specification of the halo2 Protocol [SB23]: an executable specification of halo2’s proving system, realised using hacspec.
  • implementation: hacspec_halo2
• Arithmetization of Functional Program Execution via Interaction Nets in Halo 2 [Hart22]: a description of interaction nets and how to arithmetise them in halo2 circuits.
• Arithmetization of Σ₁¹ relations with polynomial bounds in Halo 2 [HT22]: a method for compiling Σ₁¹ formulas into halo2 circuits.

standardisation

• the ZKProof Standards effort is working to standardise one zero-knowledge proof system; do get in touch if you’re interested in collaborating with one of their working groups.