50 Portfolio Project Ideas for ZK Engineers

Prove you're over 18 without revealing your actual age. Classic intro to ZK.

Prove you know a password without revealing it. Hash the password in-circuit.

Prove a number is within a range without revealing the number.

Prove membership in a set using Merkle trees. Foundation for many ZK apps.

Vote anonymously and prove you're eligible without revealing identity.

Prove you solved a Sudoku without revealing the solution.

Issue and verify credentials (degrees, certifications) without revealing holder identity.

Prove KYC compliance without revealing personal data to every service.

Prove citizenship in a country without revealing which country.

Prove reputation score is above threshold without revealing exact score or identity.

Prove you received an email from a domain without revealing email contents.

Add privacy to soulbound tokens. Prove you hold one without revealing which.

Build a Tornado Cash-style mixer. Deposit and withdraw tokens anonymously.

Prove you have sufficient balance for a transaction without revealing total balance.

Send tokens where only sender and receiver know the amount.

Prove creditworthiness without revealing financial history.

Trade tokens without linking trades to your identity.

Borrow and lend with privacy. Prove collateral without revealing portfolio.

Vote on DAO proposals without revealing your vote or token holdings.

Implement quadratic voting where vote weights are private.

Add privacy to conviction voting. Hide stake amounts and timing.

Conduct surveys where responses are verifiable but anonymous.

Full election system with registration, voting, and verifiable tallying.

Classic battleship game where board positions are committed but hidden.

Poker where hands are truly private until showdown.

Generic framework for any game with hidden information (fog of war).

Provably fair randomness for on-chain games using ZK.

Wordle where the word is committed but hidden until game ends.

Build a basic rollup that batches transactions with validity proofs.

Trustless cross-chain bridge using ZK proofs of state.

Generate proofs of Ethereum state for use in other contexts.

Batch many transactions into one proof for gas savings.

Compress on-chain data using ZK proofs (like Solana compressed NFTs).

Verify SNARKs inside SNARKs. Foundation for proof aggregation.

Implement Plonk proving system from scratch for deep understanding.

Build a simple virtual machine that generates proofs of execution.

Implement Plookup or similar for efficient lookup tables.

Design a domain-specific constraint system optimized for your use case.

Automated testing tool for Circom circuits with coverage reporting.

Visual representation of circuit constraints for debugging.

Estimate on-chain verification costs for different proof systems.

Tool to analyze and optimize circuit constraint count.

Benchmark different ZK libraries for performance and features.