ZK-Sortition: Trustless Committee Selection
committee selection for DAOs using RISC Zero
About
The problem it solves Traditional DAO committee selection often relies on centralized off-chain scripts or easily predictable on-chain randomness, both of which are vulnerable to manipulation. - ZK-Sortition provides a trustless alternative by moving the selection logic into a RISC Zero zkVM. This ensures that: - Mathematical Fairness: The selection is governed by a cryptographically secure circuit, not a black-box server. - Privacy-Preserving Proofs: We can prove the selection was fair without revealing the sensitive entropy used to generate it. - L2 Efficiency: By settling only the verified "Journal" on Base Sepolia, we keep gas costs minimal while maintaining Ethereum-level security. Use of AI tools and agents Debugging & Architecture: AI assisted in identifying the root cause of the "error code 3" EVM reverts, suggesting the pivot to an ABI-agnostic settlement strategy. Frontend Generation: Used AI to scaffold the DAO dashboard in React, integrating complex event listeners to "reveal" the committee once the Base Sepolia transaction confirmed.
How it's made
Challenges we ran into - The "Deep Issue" (ABI vs. Serde): We hit a major hurdle where the RISC Zero v3.0.5 env::commit() used Serde serialization, which caused strict Solidity abi.decode calls to revert with "error code 3". - The Fix: I engineered an ABI-agnostic settlement function in our CommitteeDraw contract that handles raw verified journal data directly, bypassing traditional padding issues. - ZK-VM Integration: Coordinating a Rust-based ZK host with a Next.js/Scaffold-ETH 2 frontend required building a custom "Proof Bridge" to pass $JOURNAL_HEX and $SEAL_HEX strings seamlessly. - Foundry TTY Sub-shells: During deployment, we encountered a TTY unreachability error when using make commands; we resolved this by bypassing the spawn chain and running forge directly with a clean environment broadcast.