Projects

halo2 has been used in some weird and wonderful circuits, including: private transfers, proof of solvency, coprocessors, machine learning models, virtual machines, zk-email, Wordle, and more.

please note that many of the projects listed here are still under development and not to be used in production.

virtual machines and execution environments

• zkEVM (Scroll): a validity proof for Ethereum transactions, powering the Scroll succinct rollup.
• Taiga (Anoma): a unified execution environment handling transparent, shielded, and private data access and operations.
• zkWASM (Delphinus Lab): the WASM virtual machine written in halo2 circuits.
• zkVM (DarkFi): a general-purpose zkSNARK virtual machine.

machine learning

• ezkl (ZKonduit): an engine for doing inference for deep learning models and other computational graphs in a zk-SNARK.
• zkml: a framework for constructing proofs of ML model execution in zk-SNARKs.

oracle

• Hyper Oracle: programmable zkOracle network, that proves execution of customizable computations, and Ethereum on-chain data via block header, and event proofs.

coprocessors

• Axiom coprocessor: prove facts about Ethereum on-chain data via aggregate block header, account, and storage proofs.

financial privacy

• Zcash Orchard: private token transfers
• Summa: zk proof of solvency

real-world protocols

• Proof of Email: prove facts about emails with the same trust assumption as the email domain.
  • demo projects: https://prove.email/
• webauthn-halo2: proving and verifying WebAuthn with halo2
• eth-voice-recovery

others

• Zordle: zk Wordle
• EigenTrust (archived): implementation of [KSM03]